dovecot: upgrade 2.2.10 -> 2.2.18

Dropped building-rquota_xdr.c-depend-on-rquota.h.patch,since 2.2.18 fixed the problem.

Update 0001-configure.ac-convert-AC_TRY_RUN-to-AC_TRY_LINK-state.patch,since
the file configure.ac has been changed.

Signed-off-by: Li Xin <lixin.fnst@cn.fujitsu.com>
Signed-off-by: Martin Jansa <Martin.Jansa@gmail.com>
Signed-off-by: Joe MacDonald <joe_macdonald@mentor.com>