SCons: Pass env to modules can_build method

This allows to disable modules based on the environment,
in particular `env[tools]` which tells us if we are
building the editor or not.

modules/bmp/config.py

@@ -1,7 +1,5 @@
-
-def can_build(platform):
+def can_build(env, platform):
     return True
 
-
 def configure(env):
     pass