Stop replacing `$your_email` with the user's email

The `$your_email` was removed from the SSH doc.

Signed-off-by: Rémy Coutable <remy@rymai.me>

app/views/help/show.html.haml

 - page_title @path.split("/").reverse.map(&:humanize)
 .documentation.wiki
-  = markdown @markdown.gsub('$your_email', current_user.try(:email) || "email@example.com")
+  = markdown @markdown

spec/features/help_pages_spec.rb

 require 'spec_helper'
 describe 'Help Pages', feature: true do
-  describe 'Show SSH page' do
-    before do
-      login_as :user
-    end
-    it 'replaces the variable $your_email with the email of the user' do
-      visit help_page_path('ssh/README')
-      expect(page).to have_content("ssh-keygen -t rsa -C \"#{@user.email}\"")
-    end
-  end
-
   describe 'Get the main help page' do
     shared_examples_for 'help page' do |prefix: ''|
       it 'prefixes links correctly' do