Utils: Drop unused headers [I-Z]

Round 2 - focus on sources.
For classes with initial in range [I-Z].
Try to keep the same separators between different kind of headers.

Change-Id: I8a7ab99bab8120ee72cda6433ee3dc6f260a4d76
Reviewed-by: hjk <hjk@qt.io>

src/libs/utils/persistentsettings.cpp

@@ -26,6 +26,7 @@
 #include "persistentsettings.h"
 
 #include "fileutils.h"
+#include "qtcassert.h"
 
 #include <QCoreApplication>
 #include <QDateTime>
@@ -43,8 +44,6 @@
 #include <QMessageBox>
 #endif
 
-#include <utils/qtcassert.h>
-
 // Read and write rectangle in X11 resource syntax "12x12+4+3"
 static QString rectangleToString(const QRect &r)
 {