Fixes for new postgresql database creation

mod/quiz/db/postgres7.sql

@@ -256,7 +256,7 @@ CREATE TABLE prefix_quiz_attemptonlast_datasets (
     category INT8  NOT NULL default '0',
     userid INT8  NOT NULL default '0',
     datasetnumber INT8  NOT NULL default '0',
-    CONSTRAINT  category UNIQUE (category,userid)
+    CONSTRAINT  prefix_quiz_attemptonlast_datasets_category_userid UNIQUE (category,userid)
 );
 
 CREATE TABLE prefix_quiz_dataset_definitions (

mod/wiki/db/postgres7.sql

@@ -56,6 +56,6 @@ CREATE TABLE prefix_wiki_pages (
 ) ;
 
 ALTER TABLE ONLY prefix_wiki_pages
-    ADD CONSTRAINT id PRIMARY KEY (pagename, version, wiki);
+    ADD CONSTRAINT prefix_wiki_pages_id PRIMARY KEY (pagename, version, wiki);
 
 CREATE INDEX prefix_wiki_pages_pagename_version_wiki_idx ON prefix_wiki_pages (pagename, version, wiki) ;