hook: even fewer parentheses for load errors

Missed this one.

mercurial/hook.py

@@ -36,7 +36,7 b' def _pythonhook(ui, repo, name, hname, f'
         d = funcname.rfind('.')
         if d == -1:
             raise error.HookLoadError(
-                _('%s hook is invalid ("%s" not in a module)')
+                _('%s hook is invalid: "%s" not in a module')
                 % (hname, funcname))
         modname = funcname[:d]
         oldpaths = sys.path

tests/test-hook.t

@@ -496,7 +496,7 b' test python hooks'
   $ hg pull ../a
   pulling from ../a
   searching for changes
-  abort: preoutgoing.nomodule hook is invalid ("nomodule" not in a module)
+  abort: preoutgoing.nomodule hook is invalid: "nomodule" not in a module
   [255]
 
   $ echo '[hooks]' > ../a/.hg/hgrc