meson: RC_LOCAL_SCRIPT_PATH_START to RC_LOCAL_PATH
RC_LOCAL_SCRIPT_PATH_START and RC_LOCAL_SCRIPT_PATH_STOP were was originally
added in the conversion to meson based on the autotools name. In
44508946 RC_LOCAL_SCRIPT_PATH_STOP was dropped.
We don't need to use such a long name.
(cherry picked from commit 452d2dfd)