php7: fix pecl build with QUILT

Commit d741a64b

 ("lang/php7: Don't run phpize7 with QUILT") changed
pecl.mk to not run phpize7 during Package/prepare if QUILT is set.  The
intention was to allow prepare, refresh and update targets to run
without building dependencies.

As a side-effect, Package/configure and Package/compile fail when QUILT
is defined because they can't find ./configure or a Makefile.  It also
impacts the github tests run with pull requests, because QUILT is
defined there.

To avoid that failure and still keep the prepare, refresh, and update
speedup, call phpize7 before Package/Configure if QUILT is defined.

Signed-off-by: Eneas U de Queiroz <cotequeiroz@gmail.com>