Bump debhelper build-depends to (>= 7.2.3~) because we use dh_bugfiles.
Bump debhelper build-depends to (>= 7.2.3~) because we use dh_bugfiles.

mswart/dovecot2deb,mswart/dovecot2deb,mswart/dovecot2deb,mswart/dovecot2deb,mswart/dovecot2deb