fix call to compile() in execute().
fix call to compile() in execute().

ChristopheVuillot/qiskit-sdk-py,atilag/qiskit-sdk-py,ChristopheVuillot/qiskit-sdk-py,QISKit/qiskit-sdk-py,atilag/qiskit-sdk-py,atilag/qiskit-sdk-py,ChristopheVuillot/qiskit-sdk-py,QISKit/qiskit-sdk-py,QISKit/qiskit-sdk-py