templater: fix truth testing of integer 0 taken from a list/dict

Broken at f9c426385853. bool(python_value) shouldn't be used here since
an integer 0 has to be truthy for backward compatibility.

mercurial/templateutil.py

@@ -350,7 +350,8 b' class hybriditem(mappable, wrapped):'
         return gen
 
     def tobool(self, context, mapping):
-        return bool(self.tovalue(context, mapping))
+        w = makewrapped(context, mapping, self._value)
+        return w.tobool(context, mapping)
 
     def tovalue(self, context, mapping):
         return _unthunk(context, mapping, self._value)

tests/test-template-functions.t

@@ -932,6 +932,8 b' Test boolean expression/literal passed t'
   rev 0 is True
   $ hg log -r 0 -T '{if(0, "literal 0 is True as well")}\n'
   literal 0 is True as well
+  $ hg log -r 0 -T '{if(min(revset(r"0")), "0 of hybriditem is also True")}\n'
+  0 of hybriditem is also True
   $ hg log -r 0 -T '{if("", "", "empty string is False")}\n'
   empty string is False
   $ hg log -r 0 -T '{if(revset(r"0 - 0"), "", "empty list is False")}\n'