Make executeRpcCall only compute rpcCallData once

This is important for distMCsAsyncTask, because currently every time
config.data is updated, wconfd generates a separate copy of the Base64
encoded, zlib compressed config.data payload string for the
/upload_file_single call sent to each master candidate's noded.

This patch causes it to generate one copy of the string and send that
in parallel to all MCs.

Signed-off-by: Brian Foley <bpfoley@google.com>
Reviewed-by: Iustin Pop <iustin@google.com>
1 file changed