[#3929] Fix for docker install. When asking sqlalchemy to create the …

…"state" table, we now specify the "public" (default) namespace so that sqlalchemy doesnt wrongly skip it due to seeing the same named table (in the tiger namespace) already created by mdillon/postgis image.

ckan/migration/versions/001_add_existing_tables.py

@@ -5,7 +5,7 @@
 
 
 def upgrade(migrate_engine):
-    meta = MetaData()
+    meta = MetaData(schema='public')
 
     state = Table('state', meta,
       Column('id', Integer() ,  primary_key=True, nullable=False),