Make use of series wildcarding
Make use of series wildcarding

The '/patch/{patchID}/mbox' endpoint now supports wildcarding for the
series number. Let's make use of it to avoid having to fetch a series
before the patch itself.

This also fixes a rather dumb bug caused by duplication of variables
names.

Signed-off-by: Stephen Finucane <06fa905d7f2aaced6dc72e9511c71a2a51e8aead@that.guru>

stephenfin/git-pw,getpatchwork/git-pw