Display username 'System' for system messages

web/react/components/post_header.jsx

@@ -34,7 +34,7 @@ export default class PostHeader extends React.Component {
             userProfile = (
                 <UserProfile
                     userId={''}
-                    overwriteName={''}
+                    overwriteName={Constants.SYSTEM_MESSAGE_PROFILE_NAME}
                     overwriteImage={Constants.SYSTEM_MESSAGE_PROFILE_IMAGE}
                     disablePopover={true}
                 />

web/react/components/rhs_root_post.jsx

@@ -167,7 +167,7 @@ export default class RhsRootPost extends React.Component {
             userProfile = (
                 <UserProfile
                     userId={''}
-                    overwriteName={''}
+                    overwriteName={Constants.SYSTEM_MESSAGE_PROFILE_NAME}
                     overwriteImage={Constants.SYSTEM_MESSAGE_PROFILE_IMAGE}
                     disablePopover={true}
                 />

web/react/utils/constants.jsx

@@ -121,6 +121,7 @@ export default {
     POST_DELETED: 'deleted',
     POST_TYPE_JOIN_LEAVE: 'system_join_leave',
     SYSTEM_MESSAGE_PREFIX: 'system_',
+    SYSTEM_MESSAGE_PROFILE_NAME: 'System',
     SYSTEM_MESSAGE_PROFILE_IMAGE: '/static/images/logo_compact.png',
     RESERVED_TEAM_NAMES: [
         'www',

web/sass-files/sass/partials/_post.scss

@@ -373,10 +373,6 @@ body.ios {
         background-color: beige;
     }
 
-	&.post--system .post__header .col__name {
-		display: none;
-	}
-
 	ul {
 		margin: 0;
 		padding: 0;