Fix ReturnInVoidContext rubocop offense

.rubocop_todo.yml

@@ -80,11 +80,6 @@ Lint/InterpolationCheck:
 Lint/MissingCopEnableDirective:
   Enabled: false
 
-# Offense count: 1
-Lint/ReturnInVoidContext:
-  Exclude:
-    - 'app/models/project.rb'
-
 # Offense count: 9
 Lint/UriEscapeUnescape:
   Exclude:

app/models/project.rb

@@ -738,11 +738,13 @@ class Project < ActiveRecord::Base
   end
 
   def import_url=(value)
-    return super(value) unless Gitlab::UrlSanitizer.valid?(value)
-
+    if Gitlab::UrlSanitizer.valid?(value)
       import_url = Gitlab::UrlSanitizer.new(value)
       super(import_url.sanitized_url)
       create_or_update_import_data(credentials: import_url.credentials)
+    else
+      super(value)
+    end
   end
 
   def import_url