Improve suggested unfreeze command

Now that frozen can be overridden when deployment is set, we can always
suggest setting that.

bundler/lib/bundler/definition.rb

@@ -361,10 +361,8 @@ def ensure_equivalent_gemfile_and_lockfile(explicit_flag = false)
              "updated #{Bundler.default_lockfile.relative_path_from(SharedHelpers.pwd)} to version control."
 
       unless explicit_flag
-        suggested_command = if Bundler.settings.locations("frozen").keys.&([:global, :local]).any?
-          "bundle config unset frozen"
-        elsif Bundler.settings.locations("deployment").keys.&([:global, :local]).any?
-          "bundle config unset deployment"
+        suggested_command = unless Bundler.settings.locations("frozen").keys.include?(:env)
+          "bundle config set frozen false"
         end
         msg << "\n\nIf this is a development machine, remove the #{Bundler.default_gemfile} " \
                "freeze \nby running `#{suggested_command}`." if suggested_command

bundler/spec/commands/update_spec.rb

@@ -659,21 +659,21 @@
 
       expect(last_command).to be_failure
       expect(err).to match(/You are trying to install in deployment mode after changing.your Gemfile/m)
-      expect(err).to match(/freeze \nby running `bundle config unset deployment`./m)
+      expect(err).to match(/freeze \nby running `bundle config set frozen false`./m)
     end
 
-    it "should suggest different command when frozen is set globally" do
+    it "should fail loudly when frozen is set globally" do
       bundle "config set --global frozen 1"
       bundle "update", :all => true, :raise_on_error => false
       expect(err).to match(/You are trying to install in deployment mode after changing.your Gemfile/m).
-        and match(/freeze \nby running `bundle config unset frozen`./m)
+        and match(/freeze \nby running `bundle config set frozen false`./m)
     end
 
-    it "should suggest different command when frozen is set globally" do
+    it "should fail loudly when deployment is set globally" do
       bundle "config set --global deployment true"
       bundle "update", :all => true, :raise_on_error => false
       expect(err).to match(/You are trying to install in deployment mode after changing.your Gemfile/m).
-        and match(/freeze \nby running `bundle config unset deployment`./m)
+        and match(/freeze \nby running `bundle config set frozen false`./m)
     end
 
     it "should not suggest any command to unfreeze bundler if frozen is set through ENV" do