Fix force_avatar_update.to_i error as force_avatar_update is a boolean

If force_avatar_update is passed in sso attributes it errors on
force_avatar_update.to_i. The SingleSignOn class forces avatar_force_update
to a boolean, so it should be treated as such.

app/models/discourse_single_sign_on.rb

@@ -126,8 +126,7 @@ class DiscourseSingleSignOn < SingleSignOn
     end
 
     if SiteSetting.sso_overrides_avatar && avatar_url.present? && (
-      avatar_force_update == "true" ||
+      avatar_force_update ||
-      avatar_force_update.to_i != 0 ||
       sso_record.external_avatar_url != avatar_url)
 
       begin

spec/models/discourse_single_sign_on_spec.rb

@@ -105,23 +105,36 @@ describe DiscourseSingleSignOn do
   end
 
   context 'when sso_overrides_avatar is enabled' do
+    let!(:sso_record) { Fabricate(:single_sign_on_record, external_avatar_url: "http://example.com/an_image.png") }
+    let!(:sso) {
+      sso = DiscourseSingleSignOn.new
+      sso.username = "test"
+      sso.name = "test"
+      sso.email = sso_record.user.email
+      sso.external_id = sso_record.external_id
+      sso
+    }
+    let(:logo) { file_from_fixtures("logo.png") }
 
     before do
       SiteSetting.sso_overrides_avatar = true
     end
 
     it "deal with no avatar url passed for an existing user with an avatar" do
-      sso_record = Fabricate(:single_sign_on_record, external_avatar_url: "http://example.com/an_image.png")
-
-      sso = DiscourseSingleSignOn.new
-      sso.username = "test"
-      sso.name = "test"
-      sso.email = sso_record.user.email
-      sso.external_id = sso_record.external_id
       # Deliberately not setting avatar_url.
 
       user = sso.lookup_or_create_user
       expect(user).to_not be_nil
     end
+
+    it "deal with no avatar_force_update passed as a boolean" do
+      FileHelper.stubs(:download).returns(logo)
+
+      sso.avatar_url = "http://example.com/a_different_image.png"
+      sso.avatar_force_update = true
+
+      user = sso.lookup_or_create_user
+      expect(user).to_not be_nil
+    end
   end
 end