Don't show the 'verify' button if the user is verified

Which is more in keeping with the designs (and we can do this now
that the new user info panel is only enabled with cross signing).

src/components/views/right_panel/UserInfo.js

@@ -1286,11 +1286,20 @@ const UserInfo = ({user, groupId, roomId, onClose}) => {
 
     const devicesSection = isRoomEncrypted ?
         (<DevicesSection loading={devices === undefined} devices={devices} userId={user.userId} />) : null;
+
+    const userVerified = cli.checkUserTrust(user.userId).isVerified();
+    let verifyButton;
+    if (!userVerified) {
+        verifyButton = <AccessibleButton className="mx_UserInfo_verify" onClick={() => verifyDevice(user.userId, null)}>
+            {_t("Verify")}
+        </AccessibleButton>;
+    }
+
     const securitySection = (
         <div className="mx_UserInfo_container">
             <h3>{ _t("Security") }</h3>
             <p>{ text }</p>
-            <AccessibleButton className="mx_UserInfo_verify" onClick={() => verifyDevice(user.userId, null)}>{_t("Verify")}</AccessibleButton>
+            {verifyButton}
             { devicesSection }
         </div>
     );