Apply pointer_follows_focus option only if it was modified

This prevents pointer being centered on a node when the option is configured.
It helps in case when xbanish only enables pointer following focus when the pointer
is visible. Which is needed to prevent 'caging' pointer on some modal dialog
windows.

Author: Dmitry Lavnikevich

src/messages.c

@@ -1698,14 +1698,22 @@ void set_setting(coordinates_t loc, char *name, char *value, FILE *rsp)
 		SET_BOOL(borderless_monocle)
 		SET_BOOL(gapless_monocle)
 		SET_BOOL(swallow_first_click)
-		SET_BOOL(pointer_follows_focus)
 		SET_BOOL(pointer_follows_monitor)
 		SET_BOOL(ignore_ewmh_focus)
 		SET_BOOL(ignore_ewmh_struts)
 		SET_BOOL(center_pseudo_tiled)
 		SET_BOOL(honor_size_hints)
 		SET_BOOL(removal_adjustment)
 #undef SET_BOOL
+	} else if (streq("pointer_follows_focus", name)) {
+		bool pff = pointer_follows_focus;
+		if (!parse_bool(value, &pointer_follows_focus)) {
+			fail(rsp, "config: %s: Invalid value: '%s'.\n", name, value);
+			return;
+		}
+		if (pff == pointer_follows_focus) {
+			return;
+		}
 #define SET_MON_BOOL(s) \
 	} else if (streq(#s, name)) { \
 		if (!parse_bool(value, &s)) { \