Revert "Check result of read_until, and return Error if 0, which indicates EOF was found before delimeter."

This reverts commit 61e888de7f.

src/main.rs

@@ -63,9 +63,6 @@ mod errors {
             SyntectError(::syntect::LoadingError);
             ParseIntError(::std::num::ParseIntError);
         }
-        errors {
-            ImmediateEOF
-        }
     }
 
     pub fn handle_error(error: &Error) {