AutoTest: Do not try to install test files

As both subprojects use files with the same name the install step
fails since using Qbs 1.5. Additionally it does not make any
sense to install these files.

Change-Id: Ib7aa9d80810f3ea3efa0df306fbce2a79cc49eac
Reviewed-by: Christian Kandeler <christian.kandeler@theqtcompany.com>

src/plugins/autotest/unit_test/mixed_atp/tests/auto/quickauto/quickauto.qbs

@@ -20,7 +20,6 @@ CppApplication {
 
     Group {
         name: "qml test files"
-        qbs.install: true
 
         files: [
             "tst_test1.qml", "tst_test2.qml", "TestDummy.qml",

src/plugins/autotest/unit_test/mixed_atp/tests/auto/quickauto2/quickauto2.qbs

@@ -19,7 +19,6 @@ CppApplication {
 
     Group {
         name: "qml test files"
-        qbs.install: true
 
         files: [ "tst_test1.qml", "tst_test2.qml" ]
     }