docs: fix error message of clientLogLevel (#2021)

Author: sottar

lib/options.json

@@ -389,7 +389,7 @@
       "bonjour": "should be {Boolean} (https://webpack.js.org/configuration/dev-server/#devserverbonjour)",
       "ca": "should be {String|Buffer}",
       "cert": "should be {String|Buffer}",
-      "clientLogLevel": "should be {String} and equal to one of the allowed values\n\n [ 'info', 'warn', 'error', 'debug', 'trace', 'silent' ]\n\n (https://webpack.js.org/configuration/dev-server/#devserverclientloglevel)",
+      "clientLogLevel": "should be {String} and equal to one of the allowed values\n\n [ 'none', 'silent', 'info', 'debug', 'trace', 'error', 'warning', 'warn' ]\n\n (https://webpack.js.org/configuration/dev-server/#devserverclientloglevel)",
       "compress": "should be {Boolean} (https://webpack.js.org/configuration/dev-server/#devservercompress)",
       "contentBase": "should be {Number|String|Array} (https://webpack.js.org/configuration/dev-server/#devservercontentbase)",
       "disableHostCheck": "should be {Boolean} (https://webpack.js.org/configuration/dev-server/#devserverdisablehostcheck)",