Use configurable github issue links more consistently

src/components/views/dialogs/BugReportDialog.tsx

@@ -233,7 +233,8 @@ export default class BugReportDialog extends React.Component<IProps, IState> {
                                     a: (sub) => (
                                         <a
                                             target="_blank"
-                                            href="https://github.com/vector-im/element-web/issues/new/choose"
+                                            href={SdkConfig.get().feedback.new_issue_url}
+                                            rel="noreferrer noopener"
                                         >
                                             {sub}
                                         </a>

src/components/views/elements/ErrorBoundary.tsx

@@ -77,7 +77,7 @@ export default class ErrorBoundary extends React.PureComponent<Props, IState> {
 
     public render(): ReactNode {
         if (this.state.error) {
-            const newIssueUrl = "https://github.com/vector-im/element-web/issues/new/choose";
+            const newIssueUrl = SdkConfig.get().feedback.new_issue_url;
 
             let bugReportSection;
             if (SdkConfig.get().bug_report_endpoint_url) {

src/components/views/rooms/RoomPreviewBar.tsx

@@ -599,7 +599,7 @@ export default class RoomPreviewBar extends React.Component<IProps, IState> {
                         {
                             issueLink: (label) => (
                                 <a
-                                    href="https://github.com/vector-im/element-web/issues/new/choose"
+                                    href={SdkConfig.get().feedback.new_issue_url}
                                     target="_blank"
                                     rel="noreferrer noopener"
                                 >