iOS: "replacing existing signature" is recognized as error instead of warning

When starting an already built app again, the default is to "build before run", which runs xcodebuild again. This lets Xcode's codesign step warn about replacing the already existing signature:

    /usr/bin/codesign --force --sign 4EC3C478DDD79D61916DD6A47C07D1622A077D08 --entitlements /private/tmp/build-ios1--Debug/ios1.build/Debug-iphoneos/ios1.build/ios1.app.xcent /tmp/build-ios1--Debug/Debug-iphoneos/ios1.app
/tmp/build-ios1--Debug/Debug-iphoneos/ios1.app: replacing existing signature

Qt Creator wrongly recognizes this as a build error, and one needs to click away the combo box "qt creator sees some errors, do you still want to run your application?".