Remove 9.0 extension install instructions

PostgreSQL 9.0 is end of life, and having both extension install methods in documentation is often a source of confusion.

diff --git a/INSTALL.md b/INSTALL.md
index 09e3b12f7827a92971c129dd4ef49dd6aa4449a5..87ba765dbcd51ac87c05d6f7f518d4066e9d63ba 100644 (file)
--- a/INSTALL.md
+++ b/INSTALL.md
@@ -160,14 +160,6 @@ bundle exec rake db:create
 
 We need to load the btree-gist extension, which is needed for showing changesets on the history tab.
 
-For PostgreSQL < 9.1 (change the version number in the path as necessary):
-
-```
-psql -d openstreetmap < /usr/share/postgresql/9.0/contrib/btree_gist.sql
-```
-
-For PostgreSQL >= 9.1:
-
 ```
 psql -d openstreetmap -c "CREATE EXTENSION btree_gist"
 ```