Segfault in ROOT compilation of sequences other than hlt1_pp_default in monitoring task

When compiling Allen with ROOT and executing the velo sequence for example, Allen crashes with the following segfault:

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#6  0x00007f6c884799d2 in ParKalmanFilter::FittedTrack::p (this=<optimized out>) at /var/home/vombruch/Allen/device/kalman/ParKalman/include/ParKalmanDefinitions.cuh:130
#7  TrackMonitor::fill (this=<optimized out>, i_buf=<optimized out>) at /var/home/vombruch/Allen/integration/monitoring/src/TrackMonitor.cpp:29
#8  0x00007f6c88476cce in MonitorManager::fill (this=<optimized out>, i_mon=<optimized out>, i_buf=0, useWallTime=<optimized out>) at /var/home/vombruch/Allen/integration/monitoring/src/MonitorManager.cpp:21
#9  0x00007f6c883e6523 in run_monitoring (mon_id=3, zmqSvc=0x2482810, monitor_manager=0x2737900, i_monitor=201) at /var/home/vombruch/Allen/main/src/AllenThreads.cpp:352
#10 0x00007f6c833279c0 in std::execute_native_thread_routine (__p=0x27cc0f0) at /build/gcc/build/contrib/gcc-9.2.0/src/gcc/9.2.0/libstdc++-v3/src/c++11/thread.cc:80
#11 0x00007f6c87be3ea5 in start_thread () from /lib64/libpthread.so.0
#12 0x00007f6c82a6796d in clone () from /lib64/libc.so.6

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The cause is most likely that Kalman tracks are not available if only the velo sequence is executed, but their quantitites are filled into monitoring histograms.

We could introduce a check that monitoring quantities are output of the configured sequence.