McuSupport: Fix missing include

Change-Id: Ie7a90edf3e4d6b289512a5bb60bca039b0b10fe3
Reviewed-by: David Schulz <david.schulz@qt.io>

src/plugins/mcusupport/mcukitmanager.cpp

@@ -31,6 +31,7 @@
 
 #include <QMessageBox>
 #include <QPushButton>
+#include <QRegularExpression>
 
 using CMakeProjectManager::CMakeConfig;
 using CMakeProjectManager::CMakeConfigItem;