add jemalloc cmake

cmake/external/jemalloc.cmake

@@ -33,4 +33,5 @@ ExternalProject_Add(
             && cp ${JEMALLOC_SOURCES_DIR}/src/extern_jemalloc/lib/libjemalloc_pic.a ${JEMALLOC_INSTALL_DIR}/lib
             && cp -r ${JEMALLOC_SOURCES_DIR}/src/extern_jemalloc/include/jemalloc  ${JEMALLOC_INCLUDE_DIR}
         TEST_COMMAND      ""
-)
\ No newline at end of file
+)
+