chore(statuses): clarify why we don't use {start, summary}CB

Instead of just commenting them out.

Signed-off-by: Raito Bezarius <raito@lix.systems>

buildbot_nix/__init__.py

@@ -881,11 +881,7 @@ class GerritNixConfigurator(ConfiguratorBase):
                                        wantSteps=True,
                                        reviewCB=gerritReviewCB,
                                        reviewArg=self.url)
-                                     #  startCB=gerritStartCB,
-                                     #  startArg=self.url,
-                                     #  summaryCB=gerritSummaryCB,
-                                     #  summaryArg=self.url)
-
+            # startCB, summaryCB are too noisy, we won't use them.
         )
 
         if self.prometheus_config is not None: