THRIFT-3760 Fix install paths etc of debian packages for py and perl

This closes #965
diff --git a/debian/substvars b/debian/substvars
index badf572..9841f2d 100644
--- a/debian/substvars
+++ b/debian/substvars
@@ -1 +1 @@
-php:Depends=phpapi-
+php:Depends=phpapi-20121212