Fix Primary Keys count.

That was broken in a recent patch refactoring the PostgreSQL SQL execute
API that now accepts a list of commands to execute.

src/sources/common/db-methods.lisp

@@ -133,7 +133,9 @@
     ;; Turn UNIQUE indexes into PRIMARY KEYS now
     ;;
     (unless data-only
-      (pgsql-execute-with-timing :post "Primary Keys" pkeys)
+      (pgsql-execute-with-timing :post "Primary Keys"
+                                 pkeys
+                                 :count (length pkeys))
 
       ;;
       ;; Foreign Key Constraints