Check for the spec version when determining private read receipt support (#9341)

Co-authored-by: Travis Ralston <travisr@matrix.org>

Author: SimonBrandner

src/components/structures/TimelinePanel.tsx

@@ -994,7 +994,8 @@ class TimelinePanel extends React.Component<IProps, IState> {
                     if (e.errcode === 'M_UNRECOGNIZED' && lastReadEvent) {
                         if (
                             !sendRRs
-                            && !cli.doesServerSupportUnstableFeature("org.matrix.msc2285.stable")
+                            && !(await cli.doesServerSupportUnstableFeature("org.matrix.msc2285.stable"))
+                            && !(await cli.isVersionSupported("v1.4"))
                         ) return;
                         try {
                             return await cli.sendReadReceipt(

src/components/views/settings/tabs/user/PreferencesUserSettingsTab.tsx

@@ -125,9 +125,12 @@ export default class PreferencesUserSettingsTab extends React.Component<IProps,
     }
 
     public async componentDidMount(): Promise<void> {
+        const cli = MatrixClientPeg.get();
+
         this.setState({
             disablingReadReceiptsSupported: (
-                await MatrixClientPeg.get().doesServerSupportUnstableFeature("org.matrix.msc2285.stable")
+                (await cli.doesServerSupportUnstableFeature("org.matrix.msc2285.stable"))
+                || (await cli.isVersionSupported("v1.4"))
             ),
         });
     }