Fixes regex for 1.8

Author: Dan McClain

lib/postgres_ext/arel/visitors/to_sql.rb

@@ -21,7 +21,7 @@ def visit_IPAddr value
       end
 
       def change_string value
-        if value.match /"|,|{/
+        if value.match /"|,|\{/
           value.gsub(/"/, "\"").gsub(/'/,'"')
         else
           value.gsub(/'/,'')