fix installation under windows

we cannot figure out what this code was supposed to be good for, and it
actually breaks stuff, so let's remove it.
patch actually by maurice.

Change-Id: I18a80af4c8b49f2a29b86ca0c0d0a08632019339
Reviewed-by: Maurice Kalinowski <maurice.kalinowski@nokia.com>

src/qtcreatorlibrary.pri

@@ -18,7 +18,6 @@ contains(QT_CONFIG, reduce_exports):CONFIG += hide_symbols
 !macx {
     win32 {
         target.path = /bin
-        target.files = $$DESTDIR/$${TARGET}.dll
     } else {
         target.path = /$$IDE_LIBRARY_BASENAME/qtcreator
     }