[rubygems/rubygems] Reword log message about current platform being missing

It reads better this way I think.

ruby/rubygems@ce9743290d

Author: deivid-rodriguez

lib/bundler/definition.rb

@@ -810,7 +810,7 @@ def change_reason
       [
         [@source_changes, "the list of sources changed"],
         [@dependency_changes, "the dependencies in your gemfile changed"],
-        [@current_platform_missing, "your lockfile does not include the current platform"],
+        [@current_platform_missing, "your lockfile is missing the current platform"],
         [@new_platforms.any?, "you are adding a new platform to your lockfile"],
         [@path_changes, "the gemspecs for path gems changed"],
         [@local_changes, "the gemspecs for git local gems changed"],

spec/bundler/commands/install_spec.rb

@@ -1368,7 +1368,7 @@ def run
     it "adds the current platform to the lockfile" do
       bundle "install --verbose"
 
-      expect(out).to include("re-resolving dependencies because your lockfile does not include the current platform")
+      expect(out).to include("re-resolving dependencies because your lockfile is missing the current platform")
       expect(out).not_to include("you are adding a new platform to your lockfile")
 
       expect(lockfile).to eq <<~L

spec/bundler/runtime/setup_spec.rb

@@ -1683,7 +1683,7 @@ def require(path)
         RUBY
       end
 
-      expect(err).to include("Your lockfile does not include the current platform, but can't be updated because file system is read-only")
+      expect(err).to include("Your lockfile is missing the current platform, but can't be updated because file system is read-only")
     end
   end
 end