Pass signals to the launcher command from the wrapper script

Without this, if the launcher is used in a Docker container, the
container will never terminate gracefully.

Author: nineinchnick

Diff for: src/main/resources/launcher

@@ -40,4 +40,4 @@ if [ ! -f "${LAUNCHER_BIN}" ]; then
   exit 1
 fi
 
-"${LAUNCHER_BIN}" "$@"
+exxec "${LAUNCHER_BIN}" "$@"