Revert "Use pushliteral instead of pushstring where possible. Saves a strlen call."

This reverts commit d69b5e60.

modules/misc/lua/libs/misc.c

@@ -99,7 +99,7 @@ static int vlclua_copyright( lua_State *L )
  *****************************************************************************/
 static int vlclua_license( lua_State *L )
 {
-    lua_pushliteral( L, LICENSE_MSG );
+    lua_pushstring( L, LICENSE_MSG );
     return 1;
 }