Fixed /usercard on linux (#1755)

- /usercard command doesn't close imidiatelly
- removed "Dialog" window flag. It seems to be unnecessary and causes issues (on left-clicking user name it sometimes didnt render unless you clicked 2-3 times.

src/controllers/commands/CommandController.cpp

@@ -453,7 +453,6 @@ QString CommandController::execCommand(const QString &textNoEmoji,
             }
             auto *userPopup = new UserInfoPopup;
             userPopup->setData(words[1], channel);
-            userPopup->setActionOnFocusLoss(BaseWindow::Delete);
             userPopup->move(QCursor::pos());
             userPopup->show();
             return "";