Fix error when snapshot exists with an underscore in the name

gns3server/controller/snapshot.py

@@ -55,12 +55,10 @@ class Snapshot:
             self._created_at = datetime.now(timezone.utc).timestamp()
             filename = self._name + "_" + datetime.fromtimestamp(self._created_at, tz=timezone.utc).replace(tzinfo=None).strftime(FILENAME_TIME_FORMAT) + ".gns3project"
         else:
-            self._name = filename.split("_")[0]
+            self._name = filename.rsplit("_", 2)[0]
             datestring = filename.replace(self._name + "_", "").split(".")[0]
-            try:
-                self._created_at = datetime.strptime(datestring, FILENAME_TIME_FORMAT).replace(tzinfo=timezone.utc).timestamp()
-            except ValueError:
-                self._created_at = datetime.now(timezone.utc)
+            self._created_at = datetime.strptime(datestring, FILENAME_TIME_FORMAT).replace(tzinfo=timezone.utc).timestamp()
+
         self._path = os.path.join(project.path, "snapshots", filename)
 
     @property