Does not build gainst boost 1.89.0 and above

[thasti]

Boost 1.89 has removed the boost_system stub library, so currently builds fail with the following error:

...
mkdir -p /tmp/ipbus-software/uhal/uhal/lib
g++ -shared -Wl,-soname,libcactus_uhal_uhal.so.2.8 -Wall -g -O3 -fPIC -Wl,--no-as-needed -lrt /tmp/ipbus-software/uhal/uhal/obj/Buffers.o /tmp/ipbus-software/uhal/uhal/obj/ClientFactory.o /tmp/ipbus-software/uhal/uhal/obj/ClientInterface.o /tmp/ipbus-software/uhal/uhal/obj/ConnectionManager.o /tmp/ipbus-software/uhal/uhal/obj/DerivedNodeFactory.o /tmp/ipbus-software/uhal/uhal/obj/HwInterface.o /tmp/ipbus-software/uhal/uhal/obj/IPbusInspector.o /tmp/ipbus-software/uhal/uhal/obj/Node.o /tmp/ipbus-software/uhal/uhal/obj/NodeTreeBuilder.o /tmp/ipbus-software/uhal/uhal/obj/ProtocolControlHub.o /tmp/ipbus-software/uhal/uhal/obj/ProtocolIPbus.o /tmp/ipbus-software/uhal/uhal/obj/ProtocolIPbusCore.o /tmp/ipbus-software/uhal/uhal/obj/ProtocolMmap.o /tmp/ipbus-software/uhal/uhal/obj/ProtocolPCIe.o /tmp/ipbus-software/uhal/uhal/obj/ProtocolTCP.o /tmp/ipbus-software/uhal/uhal/obj/ProtocolUDP.o /tmp/ipbus-software/uhal/uhal/obj/SigBusGuard.o /tmp/ipbus-software/uhal/uhal/obj/ValMem.o /tmp/ipbus-software/uhal/uhal/obj/detail/PacketFmt.o /tmp/ipbus-software/uhal/uhal/obj/detail/RobustSessionMutex.o /tmp/ipbus-software/uhal/uhal/obj/detail/SharedObject.o /tmp/ipbus-software/uhal/uhal/obj/detail/utilities.o /tmp/ipbus-software/uhal/uhal/obj/utilities/TimeIntervalStats.o /tmp/ipbus-software/uhal/uhal/obj/utilities/bits.o /tmp/ipbus-software/uhal/uhal/obj/utilities/files.o /tmp/ipbus-software/uhal/uhal/obj/utilities/xml.o -L/tmp/ipbus-software/uhal/log/lib -L/tmp/ipbus-software/uhal/grammars/lib -lpthread -lrt -lpugixml -lboost_filesystem -lboost_regex -lboost_system -lboost_chrono -lcactus_uhal_grammars -lcactus_uhal_log -o lib/libcactus_uhal_uhal.so.2.8.20
/usr/bin/ld: cannot find -lboost_system: No such file or directory
collect2: error: ld returned 1 exit status
make[2]: *** [/tmp/ipbus-software/uhal/config/mfRules.mk:97: lib/libcactus_uhal_uhal.so.2.8.20] Error 1
make[2]: Leaving directory '/tmp/ipbus-software/uhal/uhal'
make[1]: *** [Makefile:49: uhal/.virtual.Makefile] Error 2
make[1]: Leaving directory '/tmp/ipbus-software/uhal'
make: *** [Makefile:58: uhal/.virtual.Makefile] Error 2

From the boost changelog: "The stub compiled library has been removed; System has been header-only since release 1.69."