Update reference for muon triggers

Updating the reference for the changes introduced in atlas/athena!35707.

This should fix CI failures of the form:

--- /build2/ci-builds/master/Athena/build/Athena/x86_64-centos7-gcc8-opt/data/TrigAnalysisTest/ref_RDOtoRDOTrig_mt1_build.ref	2020-08-20 17:01:19.967868209 +0200
+++ ref_RDOtoRDOTrig_mt1_build.ref.new	2020-08-20 23:45:43.940731556 +0200
@@ -429,6 +429,6 @@
 TrigSignatureMoniMT                                 INFO -- #1713982776 Features                             0          0          0          0          8          8          12         10         -          -          -          -
 TrigSignatureMoniMT                                 INFO HLT_mu6_mu6noL1_L1MU6 #451489897
-TrigSignatureMoniMT                                 INFO -- #451489897 Events          10         10         0          0          0          0          10         10         10         10         6          4          -          -          6
-TrigSignatureMoniMT                                 INFO -- #451489897 Features                              0          0          0          0          14         13         16         15         9          7          -          -
+TrigSignatureMoniMT                                 INFO -- #451489897 Events          10         10         0          0          0          0          10         10         10         10         6          3          -          -          6
+TrigSignatureMoniMT                                 INFO -- #451489897 Features                              0          0          0          0          14         13         16         15         9          6          -          -
 TrigSignatureMoniMT                                 INFO HLT_mu6fast_L1MU6 #3518031697
 TrigSignatureMoniMT                                 INFO -- #3518031697 Events         10         10         0          0          0          0          10         -          -          -          -          -          -          -          10
=== Alert! FAILURE input file (+) differs from reference (-)