Parser fix of the chain names with L1 substring in the middle

Complex chain names were affected with wrong parsing if "L1" occured within the chain name. E.g. HLT_mu14_ivarloose_L1MU11_tau35_medium1_tracktwoEF_L1MU11_TAU20IM was recognized as only "mu14" and discarded "tau35". This is the fix.