Ignore if did_you_mean cannot be registered as a gem

* Fixes issue when running TruffleRuby in TravisCI with the default
  `bundle install --jobs=3 --retry=3 --deployment`.

(cherry picked from commit 5e9ff3f)

Author: eregon

lib/patches/rubygems.rb

@@ -17,7 +17,11 @@
 if Truffle::Boot.get_option 'did_you_mean' and Truffle::Boot.get_option 'rubygems'
   begin
     gem 'did_you_mean'
-  rescue LoadError => e
-    Truffle::Debug.log_warning "#{File.basename(__FILE__)}:#{__LINE__} #{e.message}"
+  rescue LoadError
+    # Ignore, this happens when GEM_HOME and GEM_PATH are set and do not include
+    # the default gem home. In such a case, did_you_mean was loaded already, but
+    # it is no longer possible to register the Gem with RubyGems. This happens
+    # for instance with 'bundle exec' after `bundle install --deployment`.
+    nil
   end
 end