text-freetype2: Fix empty text not updating source

Fixes a bug where if you update the source with empty text, it would
still continue to use the previous text value.

plugins/text-freetype2/text-freetype2.c

@@ -488,7 +488,7 @@ skip_font_load:
 		}
 	} else {
 		const char *tmp = obs_data_get_string(settings, "text");
-		if (!tmp || !*tmp)
+		if (!tmp)
 			goto error;
 
 		if (srcdata->text != NULL) {