Fix label text colour in login profile

Before labels password and username were not visible for me
because colour (dark grey) for those label was inherited from OS
which has dark theme, and background of the label was light grey.

src/loginscreen.ui

@@ -279,7 +279,7 @@
           </spacer>
          </item>
          <item>
-          <widget class="QLabel" name="label_3">
+          <widget class="QLabel" name="userNameLabel">
            <property name="text">
             <string>Username:</string>
            </property>

src/nexus.cpp

@@ -25,7 +25,6 @@
 #include "persistence/settings.h"
 #include "video/camerasource.h"
 #include "widget/gui.h"
-#include "widget/style.h"
 #include "widget/loginscreen.h"
 #include <QThread>
 #include <QDebug>
@@ -98,7 +97,6 @@ void Nexus::start()
     qRegisterMetaType<std::shared_ptr<VideoFrame>>("std::shared_ptr<VideoFrame>");
 
     loginScreen = new LoginScreen();
-    loginScreen->setStyleSheet(Style::getStylesheet(":/ui/loginScreen/loginScreen.css"));
 
 #ifdef Q_OS_MAC
     globalMenuBar = new QMenuBar(0);

src/widget/loginscreen.cpp

@@ -26,6 +26,7 @@
 #include "src/persistence/settings.h"
 #include "src/widget/form/setpassworddialog.h"
 #include "src/widget/translator.h"
+#include "src/widget/style.h"
 #include <QMessageBox>
 #include <QDebug>
 
@@ -55,6 +56,8 @@ LoginScreen::LoginScreen(QWidget *parent) :
     connect(ui->autoLoginCB, &QCheckBox::stateChanged, this, &LoginScreen::onAutoLoginToggled);
 
     reset();
+    this->setStyleSheet(Style::getStylesheet(":/ui/loginScreen/loginScreen.css"));
+
     retranslateUi();
     Translator::registerHandler(std::bind(&LoginScreen::retranslateUi, this), this);
 }

ui/loginScreen/loginScreen.css

@@ -46,3 +46,7 @@ QStackedWidget QPushButton
 #createAccountButton:hover {
   background: #0c530d;
 }
+
+QLabel {
+  color: black;
+}