start-testsuite.sh: do not override LD_LIBRARY_PATH

The Eclipse titan.core may not only be installed to hard-coded
'/usr/lib/titan' patch, but to any other location too. In the
later case, one would have to make sure that the custom path
is in $LD_LIBRARY_PATH. So we shall not override it.

Change-Id: I1ec28e8c3081d5de1bea90a7451791ac8cbbd27c
diff --git a/start-testsuite.sh b/start-testsuite.sh
index 5740d3d..31bc891 100755
--- a/start-testsuite.sh
+++ b/start-testsuite.sh
@@ -21,7 +21,8 @@
 	TEST=$3
 fi
 
-LD_LIBRARY_PATH="$SUITE_DIR:/usr/lib/titan:/usr/ttcn3/lib" ttcn3_start $SUITE $CFG $TEST
+TITAN_LIBRARY_PATH="/usr/lib/titan:/usr/ttcn3/lib"
+LD_LIBRARY_PATH="$LD_LIBRARY_PATH:$SUITE_DIR:$TITAN_LIBRARY_PATH" ttcn3_start $SUITE $CFG $TEST
 
 expected="$SUITE_DIR/expected-results.xml"
 if [ ! -f "$expected" ]; then