Fix optimize_textures.sh

utils/optimize_textures.sh

@@ -3,4 +3,4 @@
 # Colors with 0 alpha need to be preserved, because opaque leaves ignore alpha.
 # For that purpose, the use of indexed colors is disabled (-nc).
 
-find -name '../*.png' -print0 | xargs -0 optipng -o7 -zm1-9 -nc -strip all -clobber
+find .. -name '*.png' -print0 | xargs -0 optipng -o7 -zm1-9 -nc -strip all -clobber