Correct selection for make_rd_photons builder

Following discussion on #498 (closed), the requirement on ShowerShapeMax=1500 resulted being too tight and it is now replace with E19Min=0.2, i.e. ratio between central cell energy and 3x3 cluster total energy (seems ok looking at TruePhotons plot).

cc: @calvom, @tmombach, @msaur, @cagapopo

Testing rates the following lines affected by this MR:

Hlt2RD_BToMuMuGamma, Hlt2RD_BToMuEGamma, Hlt2RD_BToEEGamma from b_to_ll_hlt2
Hlt2_Bd2EtapTauTau_OS_ExclusiveLine, Hlt2_Bd2EtapTauMu_OS_ExclusiveLine, Hlt2_Bd2EtapTauE_OS_ExclusiveLine (and respective SS lines) from b_to_xtaul_hlt2
bs_to_phigamma_line, bd_to_kstgamma_line from b_to_xgamma_exclusive_hlt2
b_to_xgamma_exclusive_hlt2, obtoomgamma_omtol0k_omtol0k_lll_line from baryonic_radiative  
omega_to_xigamma_lll_line from omega_rare_decay_lines

RATES (on upgrade_minbias_hlt1_filtered)

Hlt2RD_BToEEGammaDecisionWithOutput                                                               #=14983   Sum=0           Eff=|( 0.000000 +- 0.00000 )%|
Hlt2RD_BToMuEGammaDecisionWithOutput                                                              #=14983   Sum=1           Eff=|(0.006674231 +- 0.00667401)%|
Hlt2RD_BToMuMuGammaDecisionWithOutput                                                             #=14983   Sum=1           Eff=|(0.006674231 +- 0.00667401)%|
Hlt2RD_BdToEtapTauE_EtapToPiPiGamma_TauTo3Pi_OSDecisionWithOutput                                 #=14983   Sum=0           Eff=|( 0.000000 +- 0.00000 )%|
Hlt2RD_BdToEtapTauE_EtapToPiPiGamma_TauTo3Pi_SSDecisionWithOutput                                 #=14983   Sum=1           Eff=|(0.006674231 +- 0.00667401)%|
Hlt2RD_BdToEtapTauMu_EtapToPiPiGamma_TauTo3Pi_OSDecisionWithOutput                                #=14983   Sum=1           Eff=|(0.006674231 +- 0.00667401)%|
Hlt2RD_BdToEtapTauMu_EtapToPiPiGamma_TauTo3Pi_SSDecisionWithOutput                                #=14983   Sum=0           Eff=|( 0.000000 +- 0.00000 )%|
Hlt2RD_BdToEtapTauTau_EtapToPiPiGamma_TauTo3Pi_OSDecisionWithOutput                               #=14983   Sum=0           Eff=|( 0.000000 +- 0.00000 )%|
Hlt2RD_BdToEtapTauTau_EtapToPiPiGamma_TauTo3Pi_SSDecisionWithOutput                               #=14983   Sum=1           Eff=|(0.006674231 +- 0.00667401)%|
Hlt2RD_BsToPhiGammaDecisionWithOutput                                                             #=14983   Sum=0           Eff=|( 0.000000 +- 0.00000 )%|
Hlt2RD_BdToKstGammaDecisionWithOutput                                                             #=14983   Sum=0           Eff=|( 0.000000 +- 0.00000 )%|
Hlt2RD_OmegabmToOmegamGamma_OmegamToLambda0Km_LLLDecisionWithOutput                               #=14983   Sum=1           Eff=|(0.006674231 +- 0.00667401)%|
Hlt2RD_OmegamToXimGamma_LLLDecisionWithOutput                                                     #=14983   Sum=0           Eff=|( 0.000000 +- 0.00000 )%|
Hlt2RD_XibmToXimGamma_XimToL0Pim_LLLDecisionWithOutput                                            #=14983   Sum=1           Eff=|(0.006674231 +- 0.00667401)%|