Only allow strings in URL::Sanitizer.valid?

Closes https://gitlab.com/gitlab-org/gitlab-ce/issues/55079

changelogs/unreleased/sh-ignore-arrays-url-sanitizer.yml

+---
+title: Only allow strings in URL::Sanitizer.valid?
+merge_request: 23675
+author:
+type: fixed

lib/gitlab/url_sanitizer.rb

@@ -14,6 +14,7 @@ module Gitlab
 
     def self.valid?(url)
       return false unless url.present?
+      return false unless url.is_a?(String)
 
       uri = Addressable::URI.parse(url.strip)
 

spec/lib/gitlab/url_sanitizer_spec.rb

@@ -41,6 +41,7 @@ describe Gitlab::UrlSanitizer do
       false | '123://invalid:url'
       false | 'valid@project:url.git'
       false | 'valid:pass@project:url.git'
+      false | %w(test array)
       true  | 'ssh://example.com'
       true  | 'ssh://:@example.com'
       true  | 'ssh://foo@example.com'