Fix error raised by Net::HTTPResponse#inflater if the block raises

* See https://bugs.ruby-lang.org/issues/13882#note-6

Author: eregon

lib/net/http/response.rb

@@ -268,12 +268,13 @@ def inflater # :nodoc:
 
       begin
         yield inflate_body_io
+        success = true
       ensure
-        orig_err = $!
         begin
           inflate_body_io.finish
         rescue => err
-          raise orig_err || err
+          # Ignore #finish's error if there is an exception from yield
+          raise err if success
         end
       end
     when 'none', 'identity' then