mm-decode.el (mm-dissect-buffer): Guess content-type if the first token is missing in the Content-Type header
nndoc.el (nndoc-dissect-mime-parts-sub): Ditto
nndoc.el (nndoc-dissect-mime-parts-sub): Fix last change
mm-decode.el (mm-dissect-buffer): Revert last change
nndoc.el (nndoc-dissect-mime-parts-sub): Ditto

The problem that motivated those changes was attributed to a broken
mail sender, and has been fixed.
Search the netrc entries for the logical server name, then the actual.

* nnimap.el (nnimap-open-connection-1): `auth-source-search' for the
`nnoo-current-server' first, then for the actual `nnimap-address' to
allow netrc entries for the nnoo server to coexist with netrc entries
for the `nnimap-address'.
gnus-group.el (gnus-group-browse-foreign-server):
gnus-int.el (gnus-start-news-server): Silence compiler obsolescence warning