Deal gracefully with recommendations of hidden proposals

We were seeing an exceptions in the home page when displaying
recommendations. This was due to trying to load tags of hidden proposals

With this commit we are skipping proposals that that have been hidden,
which will hopefully solve this exception

spec/models/user_spec.rb

@@ -667,6 +667,15 @@ describe User do
       expect(user.interests).to eq ["Sport"]
     end
 
+    it "deals gracefully with hidden proposals" do
+      proposal = create(:proposal, tag_list: "Sport")
+      create(:follow, followable: proposal, user: user)
+
+      proposal.hide
+
+      expect(user.interests).to eq []
+    end
+
     it "discards followed objects duplicated tags" do
       proposal1 = create(:proposal, tag_list: "Sport")
       proposal2 = create(:proposal, tag_list: "Sport")