[Qt] don't allow translation of our example btc address

src/qt/forms/sendcoinsentry.ui

@@ -51,7 +51,7 @@
       <item>
        <widget class="QValidatedLineEdit" name="payTo">
         <property name="toolTip">
-         <string>The address to send the payment to (e.g. 1NS17iag9jJgTHD1VXjvLCEnZuQ3rJDE9L)</string>
+         <string>The Bitcoin address to send the payment to</string>
         </property>
        </widget>
       </item>

src/qt/forms/signverifymessagedialog.ui

@@ -45,7 +45,7 @@
          <item>
           <widget class="QValidatedLineEdit" name="addressIn_SM">
            <property name="toolTip">
-            <string>The address to sign the message with (e.g. 1NS17iag9jJgTHD1VXjvLCEnZuQ3rJDE9L)</string>
+            <string>The Bitcoin address to sign the message with</string>
            </property>
           </widget>
          </item>
@@ -255,7 +255,7 @@
          <item>
           <widget class="QValidatedLineEdit" name="addressIn_VM">
            <property name="toolTip">
-            <string>The address the message was signed with (e.g. 1NS17iag9jJgTHD1VXjvLCEnZuQ3rJDE9L)</string>
+            <string>The Bitcoin address the message was signed with</string>
            </property>
           </widget>
          </item>

src/qt/guiutil.cpp

@@ -91,7 +91,9 @@ void setupAddressWidget(QValidatedLineEdit *widget, QWidget *parent)
 
     widget->setFont(bitcoinAddressFont());
 #if QT_VERSION >= 0x040700
-    widget->setPlaceholderText(QObject::tr("Enter a Bitcoin address (e.g. 1NS17iag9jJgTHD1VXjvLCEnZuQ3rJDE9L)"));
+    // We don't want translators to use own addresses in translations
+    // and this is the only place, where this address is supplied.
+    widget->setPlaceholderText(QObject::tr("Enter a Bitcoin address (e.g. %1)").arg("1NS17iag9jJgTHD1VXjvLCEnZuQ3rJDE9L"));
 #endif
     widget->setValidator(new BitcoinAddressEntryValidator(parent));
     widget->setCheckValidator(new BitcoinAddressCheckValidator(parent));

src/qt/signverifymessagedialog.cpp

@@ -27,7 +27,6 @@ SignVerifyMessageDialog::SignVerifyMessageDialog(QWidget *parent) :
 
 #if QT_VERSION >= 0x040700
     ui->signatureOut_SM->setPlaceholderText(tr("Click \"Sign Message\" to generate signature"));
-    ui->addressIn_VM->setPlaceholderText(tr("Enter a Bitcoin address (e.g. 1NS17iag9jJgTHD1VXjvLCEnZuQ3rJDE9L)"));
 #endif
 
     GUIUtil::setupAddressWidget(ui->addressIn_SM, this);