php-ext-pecl-r2.eclass: die earlier, and link to migration guide

eclass/php-ext-pecl-r2.eclass

@@ -34,6 +34,7 @@
 # Unlike PHP_EXT_PECL_PKG, setting this variable does not affect
 # HOMEPAGE, PHP_EXT_NAME or ${S}.
 
+die "Please upgrade to php-ext-pecl-r3 (see https://wiki.gentoo.org/wiki/Project:PHP/Php-ext-source-r3_migration_guide). This eclass is due to be removed."
 
 [[ -z "${PHP_EXT_PECL_PKG}" ]] && PHP_EXT_PECL_PKG="${PN/pecl-/}"
 
@@ -61,8 +62,6 @@ fi
 SRC_URI="http://pecl.php.net/get/${FILENAME}"
 HOMEPAGE="http://pecl.php.net/${PECL_PKG}"
 
-die "Please upgrade to php-ext-pecl-r3. This eclass is due to be removed."
-
 # @FUNCTION: php-ext-pecl-r2_src_compile
 # @DESCRIPTION:
 # Takes care of standard compile for PECL packages.