Add missing includes (qt6)

src/kmime_dateformatter.cpp

@@ -23,7 +23,7 @@
 #include <config-kmime.h>
 
 #include <QTextStream>
-
+#include <QIODevice>
 #include <KLocalizedString>
 
 using namespace KMime;

src/kmime_util.cpp

@@ -18,10 +18,10 @@
 #include "kmime_warning.h"
 
 #include <config-kmime.h>
-// #include <kdefakes.h> // for strcasestr
 
 #include <KCharsets>
 #include <QCoreApplication>
+#include <QRegExp>
 
 #include <cctype>
 #include <cstdlib>