Change the `GH_PULLREQUEST_NAMESPACE`.

Signed-off-by: Tim 'mithro' Ansell <me@mith.ro>

modules-pr-backporter/library_patch_submodules.py

diff --git a/modules-pr-backporter/library_patch_submodules.py b/modules-pr-backporter/library_patch_submodules.py
index a737697..40c1006 100644
--- a/modules-pr-backporter/library_patch_submodules.py
+++ b/modules-pr-backporter/library_patch_submodules.py
@@ -32,7 +32,7 @@
 
 __dir__ = os.path.dirname(__file__)
 
-GH_PULLREQUEST_NAMESPACE = 'pullrequest/temp/{pr_id}/{seq_id}/{branch}'
+GH_PULLREQUEST_NAMESPACE = 'backport/{pr_id}/{seq_id}/{branch}'
 
 
 def library_patch_submodules(