Fix system admin not seeing manage channel members options (#6831)

webapp/components/channel_members_dropdown/channel_members_dropdown.jsx

@@ -189,12 +189,7 @@ export default class ChannelMembersDropdown extends React.Component {
                 );
             }
 
-            if (!makeChannelMember || !makeChannelAdmin || !removeFromChannel) {
+            if ((makeChannelMember || makeChannelAdmin) && removeFromChannel) {
-                return (
-                    <div/>
-                );
-            }
-
                 return (
                     <div className='dropdown member-drop'>
                         <a
@@ -219,7 +214,10 @@ export default class ChannelMembersDropdown extends React.Component {
                         {serverError}
                     </div>
                 );
-        } else if (this.canRemoveMember() && this.props.channel.name !== Constants.DEFAULT_CHANNEL) {
+            }
+        }
+
+        if (this.canRemoveMember() && this.props.channel.name !== Constants.DEFAULT_CHANNEL) {
             return (
                 <button
                     id='removeMember'
@@ -233,7 +231,9 @@ export default class ChannelMembersDropdown extends React.Component {
                     />
                 </button>
             );
-        } else if (isChannelAdmin) {
+        }
+
+        if (isChannelAdmin) {
             if (this.props.channel.name === Constants.DEFAULT_CHANNEL) {
                 return (
                     <div/>