indent with tabs not spaces

Found these with:
git grep "^  " $(find -type  f -name \*.hs) |grep -v ':  where'

Unfortunately there is some inline hamlet that cannot use tabs for
indentation.

Also, Assistant/WebApp/Bootstrap3.hs is a copy of a module and so I'm
leaving it as-is.

Assistant/WebApp/RepoId.hs

@@ -16,7 +16,7 @@ import qualified Remote
 data RepoId
 	= RepoUUID UUID
 	| RepoName RemoteName
-  deriving (Eq, Ord, Show, Read)
+	deriving (Eq, Ord, Show, Read)
 
 mkRepoId :: Remote -> RepoId
 mkRepoId r = case Remote.uuid r of