Clean up u-c.cabal

Author: sjakobi

unordered-containers.cabal

@@ -70,7 +70,6 @@ library
     BangPatterns
 
   ghc-options: -Wall -O2 -fwarn-tabs -ferror-spans
-  -- ghc-options: -Wall -fwarn-tabs -ferror-spans
 
   -- For dumping the generated code:
   -- ghc-options: -ddump-simpl -ddump-stg-final -ddump-cmm -ddump-asm -ddump-to-file