PortAddonPullRequest: same PR description with one or multiple ported…

… PRs

Display ported PRs as list in PR description, even if only one has been
ported, so platforms like GitHub can render such list nicely with
helpful information (PR title, color and status).

oca_port/port_addon_pr.py

@@ -518,20 +518,14 @@ def _prepare_pull_request_data(self, processed_prs, blacklisted_prs):
                 f"[{self.app.target_version}][FW] {self.app.addon}: multiple ports "
                 f"from {self.app.source_version}"
             )
-            lines = [f"- #{pr['number']}" for pr in processed_prs.values()]
-            body = "\n".join(
-                [
-                    f"Port of the following PRs from {self.app.source_version} "
-                    f"to {self.app.target_version}:"
-                ]
-                + lines
-            )
         if len(processed_prs) == 1:
             pr = list(processed_prs.values())[0]
             title = f"[{self.app.target_version}][FW] {pr['title']}"
-            body = (
-                f"Port of #{pr['number']} from {self.app.source_version} "
-                f"to {self.app.target_version}."
+        if processed_prs:
+            lines = [f"- #{pr['number']}" for pr in processed_prs.values()]
+            body = "\n".join(
+                [f"Port from {self.app.source_version} to {self.app.target_version}:"]
+                + lines
             )
         # Handle blacklisted PRs
         if blacklisted_prs: