Clean up new tactical mode stats stuff

(cherry picked from commit c9bc234)

eos/saveddata/mode.py

@@ -53,8 +53,3 @@ class Mode(ItemAttrShortcut, HandledItem):
             for effect in self.item.effects.itervalues():
                 if effect.runTime == runTime and effect.activeByDefault:
                     effect.handler(fit, self, context=("module",))
-
-    def getValidCharges(self):
-        # Modes don't have charges, but it is queried for so return nothing.
-        validCharges = set()
-        return validCharges