fix e2e flag test

Signed-off-by: Tim Vaillancourt <tim@timvaillancourt.com>

go/flags/endtoend/vtctld.txt

@@ -132,7 +132,7 @@ Flags:
  --stats_emit_period duration Interval between emitting stats to all registered backends (default 1m0s)
  --stderrthreshold severityFlag logs at or above this threshold go to stderr (default 1)
  --structured-log-level logLevel The minimum log level, options: debug, info, warn, error. (default info)
- --structured-logging enable json-based structured logging
+ --structured-logging Enable json-based structured logging
  --table-refresh-interval int interval in milliseconds to refresh tables in status page with refreshRequired class
  --tablet_dir string The directory within the vtdataroot to store vttablet/mysql files. Defaults to being generated by the tablet uid.
  --tablet_grpc_ca string the server ca to use to validate servers when connecting