Remove "gemspec" from Gemfile

The local lib directory may contain an incomplete openssl library.

The "gemspec" line in Gemfile causes "bundle exec" to put the lib
directory in the load path. Although our Rakefile does not use openssl
itself, it still indirectly tries to load it as a RubyGems dependency.

Author: rhenium

Gemfile

@@ -1,7 +1,5 @@
 source "https://rubygems.org"
 
-gemspec
-
 gem "rake"
 gem "rake-compiler"
 gem "test-unit", "~> 3.0", ">= 3.4.6"