Do not store RPATH into _libgtsam_python.so

Since we're copying the .so from the build dir to python/gtsam _outside_ the
build dir, we should remove the rpath from the .so, so it will search the
library in the system, and not in the build directory, after installed using
setup.py

python/handwritten/CMakeLists.txt

@@ -16,6 +16,7 @@ add_library(${moduleName}_python SHARED exportgtsam.cpp ${gtsam_python_srcs})
 
 set_target_properties(${moduleName}_python PROPERTIES
     OUTPUT_NAME         ${moduleName}_python
+    SKIP_BUILD_RPATH TRUE
     CLEAN_DIRECT_OUTPUT 1)
 
 target_link_libraries(${moduleName}_python ${Boost_PYTHON${BOOST_PYTHON_VERSION_SUFFIX_UPPERCASE}_LIBRARY} ${PYTHON_LIBRARY} ${gtsamLib}) #temp