ibase: Fix download link

Author: vrana

reference/ibase/configure.xml

@@ -7,7 +7,7 @@
  </para>
  <para>
   &pecl.info;
-  <link xlink:href="&url.pecl.package;ibase">&url.pecl.package;ibase</link>.
+  <link xlink:href="&url.git.hub;FirebirdSQL/php-firebird">&url.git.hub;FirebirdSQL/php-firebird</link>.
  </para>
  <para>
   To enable Firebird/InterBase support configure PHP