Fix a small typo in the metrics_flags config option.

changelog.d/7171.doc

@@ -0,0 +1 @@
+Fix a small typo in the `metrics_flags` config option.

docs/sample_config.yaml

@@ -1144,7 +1144,7 @@ account_threepid_delegates:
 # enabled by default, either for performance reasons or limited use.
 #
 metrics_flags:
-    # Publish synapse_federation_known_servers, a g auge of the number of
+    # Publish synapse_federation_known_servers, a gauge of the number of
     # servers this homeserver knows about, including itself. May cause
     # performance problems on large homeservers.
     #

synapse/config/metrics.py

@@ -86,7 +86,7 @@ def generate_config_section(self, report_stats=None, **kwargs):
         # enabled by default, either for performance reasons or limited use.
         #
         metrics_flags:
-            # Publish synapse_federation_known_servers, a g auge of the number of
+            # Publish synapse_federation_known_servers, a gauge of the number of
             # servers this homeserver knows about, including itself. May cause
             # performance problems on large homeservers.
             #