pySim-trace_test.sh: Force termcolor to suppress color generation

on some systems, the output would otherwise contain colored status
words, which in turn mean the test otuput no longer matches the expected
output.

Change-Id: Icb700f6e85a285748e00367a398975aa5e75dec5

tests/pySim-trace_test.sh

@@ -25,6 +25,8 @@ GSMTAP_TRACE=pySim-trace_test_gsmtap.pcapng
 TEMPFILE=temp.tmp
 
 export PYSIM_INTEGRATION_TEST=1
+# to avoid termcolor.colored generating colors; https://github.com/termcolor/termcolor
+export ANSI_COLORS_DISABLED=1
 
 echo "pySim-trace_test - a test program to test pySim-trace.py"
 echo "========================================================"