Remove warning about track_associations default

Failing to set PaperTrail.config.track_associations will no longer produce
a warning. The default (false) will remain the same.

lib/paper_trail/config.rb

@@ -18,18 +18,17 @@ module PaperTrail
       @serializer = PaperTrail::Serializers::YAML
     end
 
-    # Previously, we checked `PaperTrail::VersionAssociation.table_exists?`
+    # As of PaperTrail 5, `track_associations?` defaults to false. Tracking
+    # associations is an experimental feature so we recommend setting
+    # PaperTrail.config.track_associations = false in your
+    # config/initializers/paper_trail.rb
+    #
+    # In PT 4, we checked `PaperTrail::VersionAssociation.table_exists?`
     # here, but that proved to be problematic in situations when the database
     # connection had not been established, or when the database does not exist
     # yet (as with `rake db:create`).
     def track_associations?
       if @track_associations.nil?
-        ActiveSupport::Deprecation.warn <<-EOS.strip_heredoc.gsub(/\s+/, " ")
-          PaperTrail.config.track_associations has not been set. As of PaperTrail 5, it
-          defaults to false. Tracking associations is an experimental feature so
-          we recommend setting PaperTrail.config.track_associations = false in
-          your config/initializers/paper_trail.rb
-        EOS
         false
       else
         @track_associations

spec/paper_trail/config_spec.rb

@@ -16,16 +16,14 @@ module PaperTrail
 
     describe "track_associations?" do
       context "@track_associations is nil" do
-        after do
-          PaperTrail.config.track_associations = true
-        end
-
         it "returns false and prints a deprecation warning" do
           config = described_class.instance
           config.track_associations = nil
-          expect {
-            expect(config.track_associations?).to eq(false)
-          }.to output(/DEPRECATION WARNING/).to_stderr
+          expect(config.track_associations?).to eq(false)
+        end
+
+        after do
+          PaperTrail.config.track_associations = true
         end
       end
     end