QmakeProject: Fix mergeLists which lead to cumulative parse being ignored
QmakeProject: Fix mergeLists which lead to cumulative parse being ignored

Any .pri files only found via cumulative parsing were ignored.

Task-number: QTCREATORBUG-13181
Change-Id: I1a7a639097b38a4ce1de01824be196a0c2781e84
Reviewed-by: Robert Loehning <1f928983f879a6fe326acd94487f754cc16e1fe4@digia.com>
Reviewed-by: Tobias Hunger <012f8d714267bccc9d4766fbeace9f175fcc70c4@theqtcompany.com>

amyvmiwei/qt-creator,xianian/qt-creator,xianian/qt-creator,amyvmiwei/qt-creator,danimo/qt-creator,kuba1/qtcreator,danimo/qt-creator,xianian/qt-creator,danimo/qt-creator,xianian/qt-creator,Distrotech/qtcreator,kuba1/qtcreator,amyvmiwei/qt-creator,kuba1/qtcreator,martyone/sailfish-qtcreator,farseerri/git_code,AltarBeastiful/qt-creator,martyone/sailfish-qtcreator,xianian/qt-creator,xianian/qt-creator,amyvmiwei/qt-creator,amyvmiwei/qt-creator,amyvmiwei/qt-creator,martyone/sailfish-qtcreator,danimo/qt-creator,farseerri/git_code,farseerri/git_code,Distrotech/qtcreator,farseerri/git_code,AltarBeastiful/qt-creator,Distrotech/qtcreator,AltarBeastiful/qt-creator,AltarBeastiful/qt-creator,danimo/qt-creator,farseerri/git_code,martyone/sailfish-qtcreator,Distrotech/qtcreator,martyone/sailfish-qtcreator,martyone/sailfish-qtcreator,farseerri/git_code,danimo/qt-creator,xianian/qt-creator,AltarBeastiful/qt-creator,kuba1/qtcreator,kuba1/qtcreator,Distrotech/qtcreator,kuba1/qtcreator,danimo/qt-creator,danimo/qt-creator,martyone/sailfish-qtcreator,martyone/sailfish-qtcreator,farseerri/git_code,xianian/qt-creator,farseerri/git_code,AltarBeastiful/qt-creator,martyone/sailfish-qtcreator,AltarBeastiful/qt-creator,danimo/qt-creator,kuba1/qtcreator,Distrotech/qtcreator,xianian/qt-creator,kuba1/qtcreator,amyvmiwei/qt-creator,Distrotech/qtcreator,kuba1/qtcreator,amyvmiwei/qt-creator,AltarBeastiful/qt-creator