kdiff3: fix application crash on files with tabulation

Author: u-235

3rdparty/kdiff3/optiondialog.cpp

@@ -641,7 +641,7 @@ class OptionEncodingComboBox : public QComboBox, public OptionItem
 
 OptionDialog::OptionDialog(QWidget *parent) : QTabWidget(parent)
 {
-
+    setupEditPage();
     setupFontPage();
     setupColorPage();
     setupOtherOptions();