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.

Types/Crypto.hs

@@ -59,10 +59,10 @@ readMac "HMACSHA512" = Just HmacSha512
 readMac _ = Nothing
 
 calcMac
-  :: Mac	  -- ^ MAC
-  -> L.ByteString -- ^ secret key
-  -> L.ByteString -- ^ message
-  -> String	  -- ^ MAC'ed message, in hexadecimals
+	:: Mac          -- ^ MAC
+	-> L.ByteString -- ^ secret key
+	-> L.ByteString -- ^ message
+	-> String       -- ^ MAC'ed message, in hexadecimal
 calcMac mac = case mac of
 	HmacSha1   -> showDigest $* hmacSha1
 	HmacSha224 -> showDigest $* hmacSha224

Types/ScheduledActivity.hs

@@ -17,7 +17,7 @@ import Data.Either
 data ScheduledActivity 
 	= ScheduledSelfFsck Schedule Duration
 	| ScheduledRemoteFsck UUID Schedule Duration
-  deriving (Eq, Read, Show, Ord)
+	deriving (Eq, Read, Show, Ord)
 
 {- Activities that run on a remote, within a time window, so
  - should be run when the remote gets connected. -}