try to fix linking against HexExStatic from shared lib

CMakeLists.txt

@@ -125,6 +125,7 @@ set_target_properties (HexExStatic
     DEFINE_SYMBOLS "-DHEXEX_EXPORT_SYMBOLS"
     CXX_STANDARD 11
     )
+set_property(TARGET HexExStatic PROPERTY POSITION_INDEPENDENT_CODE ON)
 
 set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS}")