fix returned status for integration errors
fix returned status for integration errors

paulstapor/AMICI,paulstapor/AMICI,AMICI-developer/AMICI,AMICI-developer/AMICI,AMICI-developer/AMICI,paulstapor/AMICI,AMICI-developer/AMICI,FFroehlich/AMICI,FFroehlich/AMICI,FFroehlich/AMICI,paulstapor/AMICI,FFroehlich/AMICI