Updating Site URL help text in System Console (#6582)

* Updating Site URL help text in System Console

* Replacing single quotes with double quotes

* Corrected statement about non-standard ports

* Converted double quotes to single quotes

webapp/components/admin_console/configuration_settings.jsx

@@ -105,7 +105,7 @@ export default class ConfigurationSettings extends AdminSettings {
                     helpText={
                         <FormattedMessage
                             id='admin.service.siteURLDescription'
-                            defaultMessage='The URL, including port number and protocol, that users will use to access Mattermost. This setting is required.'
+                            defaultMessage='The URL that users will use to access Mattermost. Standard ports, such as 80 and 443, can be omitted, but non-standard ports are required. For example: http://mattermost.example.com:8065. This setting is required.'
                         />
                     }
                     value={this.state.siteURL}

webapp/i18n/en.json

@@ -746,7 +746,7 @@
   "admin.service.sessionCacheDesc": "The number of minutes to cache a session in memory.",
   "admin.service.sessionDaysEx": "E.g.: \"30\"",
   "admin.service.siteURL": "Site URL:",
-  "admin.service.siteURLDescription": "The URL, including port number and protocol, that users will use to access Mattermost. This setting is required.",
+  "admin.service.siteURLDescription": "The URL that users will use to access Mattermost. Standard ports, such as 80 and 443, can be omitted, but non-standard ports are required. For example: http://mattermost.example.com:8065. This setting is required.",
   "admin.service.siteURLExample": "E.g.: \"https://mattermost.example.com:1234\"",
   "admin.service.ssoSessionDays": "Session length SSO (days):",
   "admin.service.ssoSessionDaysDesc": "The number of days from the last time a user entered their credentials to the expiry of the user's session. If the authentication method is SAML or GitLab, the user may automatically be logged back in to Mattermost if they are already logged in to SAML or GitLab. After changing this setting, the setting will take effect after the next time the user enters their credentials.",