fix(ui): fixed typos of pseudo-states in stylesheets

Some pseudo-states were wrongly addressed with `::` instead of `:` in
stylesheets.

ui/emoticonWidget/emoticonWidget.css

@@ -13,7 +13,7 @@ QRadioButton::indicator
      height: 10px;
 }
 
-QRadioButton::indicator::unchecked
+QRadioButton::indicator:unchecked
 {
      image: url(:/ui/emoticonWidget/dot_page.svg);
 }
@@ -28,7 +28,7 @@ QRadioButton::indicator:unchecked:pressed
      image: url(:/ui/emoticonWidget/dot_page_hover.svg);
 }
 
-QRadioButton::indicator::checked
+QRadioButton::indicator:checked
 {
      image: url(:/ui/emoticonWidget/dot_page_current.svg);
 }

ui/loginScreen/loginScreen.css

@@ -53,6 +53,6 @@ QLabel, QCheckBox, QProgressBar {
   color: black;
 }
 
-QCheckBox::disabled {
+QCheckBox:disabled {
   color: gray;
 }