Update build_sdk.sh
Update build_sdk.sh

libdl needed when building curl when linking it against static OpenSSL, or cURL doesn't configure with the SSL feature enabled.  MEGAcli detects this on startup by inspecting the cURL feature flags.
meganz/sdk,Acidburn0zzz/sdk,meganz/sdk,meganz/sdk,Acidburn0zzz/sdk,Acidburn0zzz/sdk,meganz/sdk,meganz/sdk,Acidburn0zzz/sdk,Acidburn0zzz/sdk,meganz/sdk,Acidburn0zzz/sdk,meganz/sdk,Acidburn0zzz/sdk,Acidburn0zzz/sdk