Fix:

error: ‘for’ loop initial declaration used outside C99 mode

https://github.com/BlueM/cliclick/pull/113
--- Actions/MouseBaseAction.m.orig	2020-10-01 16:20:58.000000000 -0500
+++ Actions/MouseBaseAction.m	2020-10-01 16:31:49.000000000 -0500
@@ -166,3 +166,4 @@
 
-    for (unsigned i = 0; i < steps; i ++) {
+    unsigned i;
+    for (i = 0; i < steps; i ++) {
         float factor = [self cubicEaseInOut:(stepSize * i)];