test-pkcs11-tool-test-threads.sh - skip if opensc-tool not present

As suggested in PR comments

 On branch X25519-improvements-2
 Changes to be committed:
	modified:   tests/test-pkcs11-tool-test-threads.sh

tests/test-pkcs11-tool-test-threads.sh

@@ -20,6 +20,17 @@ fi
 echo "======================================================="
 echo "Test pkcs11 threads IN "
 echo "======================================================="
+OPENSC_TOOL="../src/tools/opensc-tool"
+echo "check for opensc-tool"
+if [[ -f $OPENSC_TOOL ]] ; then
+echo "trying opensc-tool -a"
+	$OPENSC_TOOL -a
+	if [[ "$?" -ne "0" ]] ; then
+		echo "No token found, skipping Test pkcs11 threads "
+		exit 77
+	fi
+fi
+
 $PKCS11_TOOL --test-threads IN -L --module="$P11LIB"
 assert $? "Failed running tests"