rbenv-rehash: remove superfluous trap signals

A trap on the special signal EXIT is executed before the shell
terminates. EXIT actually covers SIGINT and SIGTERM as well, and
we don't need any extra traps for them.

See bash(1) and "help trap" in bash.

libexec/rbenv-rehash

@@ -22,7 +22,7 @@ set +o noclobber
 
 # If we were able to obtain a lock, register a trap to clean up the
 # prototype shim when the process exits.
-trap remove_prototype_shim SIGINT SIGTERM EXIT
+trap remove_prototype_shim EXIT
 
 remove_prototype_shim() {
   rm -f "$PROTOTYPE_SHIM_PATH"