Enable strictPropertyInitialization (#11203)

src/components/views/auth/CaptchaForm.tsx

@@ -117,7 +117,7 @@ export default class CaptchaForm extends React.Component<ICaptchaFormProps, ICap
             });
         } catch (e) {
             this.setState({
-                errorText: e.toString(),
+                errorText: e instanceof Error ? e.message : String(e),
             });
         }
     }

src/components/views/auth/InteractiveAuthEntryComponents.tsx

@@ -647,7 +647,7 @@ export class MsisdnAuthEntry extends React.Component<IMsisdnAuthEntryProps, IMsi
                 });
             }
         } catch (e) {
-            this.props.fail(e);
+            this.props.fail(e instanceof Error ? e : new Error("Failed to submit msisdn token"));
             logger.log("Failed to submit msisdn token");
         }
     };