dev-php/pecl-ssh2: new v0.13 revision supporting PHP_TARGETS=php7-1.

dev-php/pecl-ssh2: new v0.13 revision supporting PHP_TARGETS=php7-1.

The SLOT=0 for this package supports php-5.x, while SLOT=7 supports
php-7.x. To get them both installed at the same time, we use some
weird trickery. Long story short, we need to add a special case to
the SLOT=0 ebuild supporting "php7-1" in PHP_TARGETS.

The previous commit added php-7.1 support to the SLOT=7 ebuilds, and
this commit adds it to the SLOT=0 ebuild.

Gentoo-Bug: 603508

Package-Manager: Portage-2.3.3, Repoman-2.3.1