Use -rpath in order to predefine location for linked snap7 library

silecs-diagnostic-cpp/Makefile.dep

@@ -31,3 +31,6 @@ DEPENDENT_LINKER_OPTIONS += -L$(BOOST_HOME)/lib/$(CPU)
 DEPENDENT_LINKER_OPTIONS += -L/usr/lib64 -lxml2
 DEPENDENT_LINKER_OPTIONS += -lsilecs-comm
 DEPENDENT_LINKER_OPTIONS += -lstdc++ -lxml2 -lboost_system -lboost_filesystem -lcurl -lQtGui -lQtCore
+
+DEPENDENT_LINKER_OPTIONS += -Wl,-rpath=$(SNAP7_BASE)/build/bin/$(CPU)-linux
+