Add ImportError to check_log patterns

Surprisingly, we didn't have "ImportError" in check_log patterns, so if anyone imported a non-existent python module, we wouldn't get the message with the module name in the check_log output. After this MR, we should catch also errors like this:

ImportError: No module named JetSequenceDefs

Trigger/TrigValidation/TrigValTools/bin/check_log.pl

@@ -101,7 +101,7 @@ sub scan_logfile(){
   @patterns=();
   if ($errors) {
       push @patterns, "^ERROR | ERROR | FATAL |CRITICAL |ABORT_CHAIN ";
-      push @patterns, "^Exception\:|^Caught signal|^Core dump|Traceback|Shortened traceback|stack trace|^Algorithm stack\:|IncludeError|inconsistent use of tabs and spaces in indentation|glibc detected|tcmalloc\: allocation failed"
+      push @patterns, "^Exception\:|^Caught signal|^Core dump|Traceback|Shortened traceback|stack trace|^Algorithm stack\:|IncludeError|ImportError|inconsistent use of tabs and spaces in indentation|glibc detected|tcmalloc\: allocation failed"
       }
   if ($warnings) {
       push @patterns, "WARNING ";