passphrasedialog: change dialog title to "Passphrase Dialog" / remove style-sheet for bold font and use Qt Designer option / remove an unused label default-text and remove an obsolete clear()'

src/qt/askpassphrasedialog.cpp

@@ -24,7 +24,6 @@ AskPassphraseDialog::AskPassphraseDialog(Mode mode, QWidget *parent) :
     ui->passEdit1->installEventFilter(this);
     ui->passEdit2->installEventFilter(this);
     ui->passEdit3->installEventFilter(this);
-    ui->capsLabel->clear();
 
     switch(mode)
     {

src/qt/forms/askpassphrasedialog.ui

@@ -23,7 +23,7 @@
    </size>
   </property>
   <property name="windowTitle">
-   <string>Dialog</string>
+   <string>Passphrase Dialog</string>
   </property>
   <layout class="QVBoxLayout" name="verticalLayout">
    <item>
@@ -88,13 +88,14 @@
      </item>
      <item row="4" column="1">
       <widget class="QLabel" name="capsLabel">
-       <property name="styleSheet">
+       <property name="font">
-        <string notr="true">#capsLabel {
+        <font>
-	font: bold;
+         <weight>75</weight>
-}</string>
+         <bold>true</bold>
+        </font>
        </property>
        <property name="text">
-        <string>TextLabel</string>
+        <string/>
        </property>
        <property name="alignment">
         <set>Qt::AlignCenter</set>