(GH-585/CONT-998) Fix for safe_directory logic

Due to  mistake in the logic unsafe directory was previously removed on every other run.
The logic previously checked whether the unsafe directory needed to be added, removing it if this was false without taking into account when it was already set but we wanted it to be left in place.

Author: david22swan

lib/puppet/provider/vcsrepo/git.rb

@@ -609,7 +609,7 @@ def update_safe_directory
 
     if should_add_safe_directory?
       add_safe_directory
-    else
+    elsif should_remove_safe_directory?
       remove_safe_directory
     end
   end
@@ -637,6 +637,12 @@ def should_add_safe_directory?
       !safe_directories.include?(@resource.value(:path)) # directory should not already be in the list
   end
 
+  # @!visibility private
+  def should_remove_safe_directory?
+    (!@resource.value(:safe_directory) && # safe_directory should be false
+      safe_directories.include?(@resource.value(:path)) # directory should be in the list
+  end
+
   # @!visibility private
   def git_remote_action(*args)
     proxy = @resource.value(:http_proxy)