Fixed project settings alert colors

In another MR, the class name was changed making all the alert messages have no background color

app/views/projects/deploy_keys/index.html.haml

@@ -19,7 +19,7 @@
       %ul.well-list
         = render @enabled_keys
     - else
-      .profile-settings-message.text-center
+      .settings-message.text-center
         No deploy keys found. Create one with the form above or add existing one below.
     %h5.prepend-top-default
       Deploy keys from projects you have access to (#{@available_project_keys.size})
@@ -27,7 +27,7 @@
       %ul.well-list
         = render @available_project_keys
     - else
-      .profile-settings-message.text-center
+      .settings-message.text-center
         No deploy keys from your projects could be found. Create one with the form above or add existing one below.
     - if @available_public_keys.any?
       %h5.prepend-top-default

app/views/projects/hooks/index.html.haml

@@ -80,5 +80,5 @@
         - @hooks.each do |hook|
           = render "project_hook", hook: hook
     - else
-      %p.profile-settings-message.text-center.append-bottom-0
+      %p.settings-message.text-center.append-bottom-0
         No webhooks found, add one in the form above.

app/views/projects/protected_branches/_branches_list.html.haml

@@ -1,7 +1,7 @@
 %h5.prepend-top-0
   Already Protected (#{@branches.size})
 - if @branches.empty?
-  %p.profile-settings-message.text-center
+  %p.settings-message.text-center
     No branches are protected, protect a branch with the form above.
 - else
   - can_admin_project = can?(current_user, :admin_project, @project)

app/views/projects/triggers/index.html.haml

@@ -18,7 +18,7 @@
             %th
           = render partial: 'trigger', collection: @triggers, as: :trigger
     - else
-      %p.profile-settings-message.text-center.append-bottom-default
+      %p.settings-message.text-center.append-bottom-default
         There are no triggers to use, add one by the button below.
 
     = form_for @trigger, url: url_for(controller: 'projects/triggers', action: 'create') do |f|