Build QMLObserver and qmldump only in debug mode

The problem is that we actually should have both debug & release builds,
but we don't have detection at the moment which binary to use.
See QTCREATORBUG-2496

Reviewed-by: Thomas Hartmann

share/qtcreator/qml/qmldump/qmldump.pro

@@ -8,6 +8,10 @@ TARGET = qmldump
 QT += declarative
 CONFIG += console
 
+### FIXME: only debug plugins are now supported.
+CONFIG -= release
+CONFIG += debug
+
 TEMPLATE = app
 
 SOURCES += main.cpp

share/qtcreator/qml/qmlobserver/qmlobserver.pro

 TEMPLATE = app
 DEFINES += QMLOBSERVER
 
+### FIXME: only debug plugins are now supported.
+CONFIG -= release
+CONFIG += debug
+
 include(qml.pri)
 
 SOURCES += main.cpp