TT#12307 Check for existing of /var/cores/core.perl-fcgi.sig11* before moving them

We have kamilio coredumps in CE stretch, though system-tests
access all /var/cores/core.* and only renames
/var/cores/core.perl-fcgi.sig11* then. This fails of course:

| ================== NOTE: CORE DUMP DETECTED ==================
| = Removing known cores to prevent failing for the known issues:
| = 1) MT#21791: Renaming ngcp-panel cores /var/cores/core.perl-fcgi.sig11*
| ls: cannot access '/var/cores/core.perl-fcgi.sig11*': No such file or directory
| Connection to 192.168.22.197 closed.
| + RC=2

So if we want to rename the /var/cores/core.perl-fcgi.sig11*
only then also test only for them.

Change-Id: I562982943d5b0b0b053cf62c54fba6fa45950331

testrunner

@@ -20,7 +20,7 @@ case "${TYPE}" in
   *) echo "ERRRO: Unknown type '$1'" >&2 ; usage >&2 ; exit 1 ;;
 esac
 
-if ls /var/cores/core.* >/dev/null 2>&1 ; then
+if ls /var/cores/core.perl-fcgi.sig11* >/dev/null 2>&1 ; then
   echo "================== NOTE: CORE DUMP DETECTED =================="
   echo "= Removing known cores to prevent failing for the known issues:"
   echo "= 1) MT#21791: Renaming ngcp-panel cores /var/cores/core.perl-fcgi.sig11*"