external_rules.cmake: do not overwrite leveldb.cmake from firestore

Author: dconeybe

cmake/external_rules.cmake

@@ -134,11 +134,6 @@ function(download_external_sources)
         "\n#include <stdlib.h>\n")
       endif()
     endif()
-    if (FIREBASE_INCLUDE_FIRESTORE)
-      # Tweak Firestore's included version of leveldb to match our own.
-      file(INSTALL "${PROJECT_SOURCE_DIR}/cmake/external/leveldb.cmake"
-           DESTINATION "${PROJECT_BINARY_DIR}/external/src/firestore/cmake/external")
-    endif()
   endif()
 endfunction()