python3 shebang lines

contrib/contributors.py

@@ -1,4 +1,4 @@
-#!/usr/bin/python3
+#!/usr/bin/env python3
 """Update the contributor list
 
 Alias handling is done by git with .mailmap

contrib/cyrillic_convert.py

@@ -1,4 +1,4 @@
-#!/usr/bin/python3
+#!/usr/bin/env python3
 
 """Convert gibberish back into Cyrillic"""
 

contrib/gallery.py

@@ -1,3 +1,4 @@
+#!/usr/bin/env python3
 """
 Outputs a huge image with all currently-supported block textures.
 """

contrib/playerInspect.py

@@ -1,3 +1,4 @@
+#!/usr/bin/env python3
 """
 Very basic player.dat inspection script
 """