bullseye: Don't fail for non-existent projects

We don't necessarily have all projects in our tree that we get patches
for, so gracefully handle non-existent projects. An example is
bootable/recovery: We use TWRP instead of AOSP recovery.

Change-Id: I6ff630c4159095622e99ab2f6bd3dd5e2294be40
diff --git a/bullseye/bulletin.py b/bullseye/bulletin.py
index 632c1d8..041efaf 100644
--- a/bullseye/bulletin.py
+++ b/bullseye/bulletin.py
@@ -279,18 +279,21 @@
                 else False
             )
             if snippet_match:
-                patches.append(
-                    KernelPatch(
-                        self._archive,
-                        item,
-                        "A-" + snippet_match.group("android_id"),
-                        self._manifest,
-                        self._args,
-                        snippet_match.group("subpatch"),
-                        snippet_match.group("kernel"),
-                        snippet_match.group("extra"),
+                try:
+                    patches.append(
+                        KernelPatch(
+                            self._archive,
+                            item,
+                            "A-" + snippet_match.group("android_id"),
+                            self._manifest,
+                            self._args,
+                            snippet_match.group("subpatch"),
+                            snippet_match.group("kernel"),
+                            snippet_match.group("extra"),
+                        )
                     )
-                )
+                except ProjectNotFoundError as e:
+                    print("[BE]: WARNING: {}".format(e))
             elif (
                 platform
                 and "android-{}".format(android_version) in item
@@ -299,11 +302,14 @@
                 issues = self._issue_mapping.get(item, None)
                 # TODO: `issues` will always be None, also before the latest
                 # refactoring.
-                patches.append(
-                    PlatformPatch(
-                        self._archive, item, issues, self._manifest, self._args
+                try:
+                    patches.append(
+                        PlatformPatch(
+                            self._archive, item, issues, self._manifest, self._args
+                        )
                     )
-                )
+                except ProjectNotFoundError as e:
+                    print("[BE]: WARNING: {}".format(e))
 
         return patches