Drop unnecessary include_directories(${DAVIX_INCLUDE_DIRS})

This include directory is now added automatically by the imported
target for Davix.

net/davix/CMakeLists.txt

@@ -3,8 +3,5 @@
 # @author Pere Mato, CERN
 ############################################################################
 
-include_directories(${DAVIX_INCLUDE_DIRS})
-
 ROOT_ADD_CXX_FLAG(CMAKE_CXX_FLAGS -Wno-deprecated-declarations) # Davix getAllReplicas
-
 ROOT_STANDARD_LIBRARY_PACKAGE(RDAVIX LIBRARIES Davix::Davix DEPENDENCIES RIO Net)