remove overly restrictive check from Command c'tor
remove overly restrictive check from Command c'tor

Both parameters can be set as properties after constructing the object.

Change-Id: I59b52eb4a4b4a629b0c0a9c2f509f1b940c3d945
Reviewed-by: Christian Kandeler <3aa99dcdd3f0cac61fb81c2a11771c0cc2497607@digia.com>

gatzka/qt-labs-qbs,villytiger/qbs,Distrotech/qbs,qt-labs/qbs,qtproject/qt-labs-qbs,Distrotech/qbs,gatzka/qt-labs-qbs,gatzka/qt-labs-qbs,villytiger/qbs,qt-labs/qbs,Distrotech/qbs,villytiger/qbs,gatzka/qt-labs-qbs,gatzka/qt-labs-qbs,Distrotech/qbs,gatzka/qt-labs-qbs,qtproject/qt-labs-qbs,villytiger/qbs,Distrotech/qbs,qt-labs/qbs,qtproject/qt-labs-qbs,villytiger/qbs,qtproject/qt-labs-qbs,gatzka/qt-labs-qbs,qtproject/qt-labs-qbs,qtproject/qt-labs-qbs,qt-labs/qbs,qt-labs/qbs,Distrotech/qbs,qt-labs/qbs,Distrotech/qbs,qtproject/qt-labs-qbs,qt-labs/qbs,villytiger/qbs