docs: clear sourceLabels (#1955)

* docs: clear sourceLabels

Signed-off-by: Long Dai <long0dai@foxmail.com>

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Signed-off-by: Long Dai <long0dai@foxmail.com>

* feedback

Signed-off-by: Long Dai <long0dai@foxmail.com>

Author: daixiang0

networking/v1alpha3/virtual_service.gen.json

@@ -1069,9 +1069,9 @@ message HTTPMatchRequest {
   // in these cases it is not required to explicitly select the port.
   uint32 port = 6;
 
-  // One or more labels that constrain the applicability of a rule to
-  // workloads with the given labels. If the VirtualService has a list of
-  // gateways specified in the top-level `gateways` field, it must include the reserved gateway
+  // One or more labels that constrain the applicability of a rule to source (client) workloads
+  // with the given labels. If the VirtualService has a list of gateways specified
+  // in the top-level `gateways` field, it must include the reserved gateway
   // `mesh` for this field to be applicable.
   map<string, string> source_labels = 7;