Match the recent api change to rc_strlist_join also. We now free the 2nd list for ease of use.

src/runscript.c

@@ -1049,7 +1049,7 @@ int runscript (int argc, char **argv)
 		/* Ensure our environment is pure
 		   Also, add our configuration to it */
 		env = rc_filter_env ();
-		env = rc_strlist_join (env, rc_make_env ());
+		rc_strlist_join (&env, rc_make_env ());
 
 		if (env) {
 			char *p;