Fix PLMN ID for SessionManagementSubscriptionData (HTTP2)

Fix PLMN ID in HTTP request URL for SessionManagementSubscriptionData (HTTP2)

added v1.5.1 label

assigned to @tien-thinh.nguyen

OAI OAI-CN5G-UDR build (132): passed (https://jenkins-oai.eurecom.fr/job/OAI-CN5G-UDR/132/)

mentioned in merge request oai-cn5g-fed!115 (merged)

approved this merge request

mentioned in commit c466af27

merged