package/dovecot: drop first patch

First patch is not needed since version 2.3.0 and
https://github.com/dovecot/core/commit/08259c1f206026ca9b9f4b4e97603943c6093def



Signed-off-by: Fabrice Fontaine <fontaine.fabrice@gmail.com>
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>