Fix: Updating last_message_id after each batch

[Lqlsoftware]

Patch for updating last_message_id after each batch.
Adding Sock5 proxy usage in README.md by the document of Pyrogram

[codecov]

Codecov Report

Merging #50 (1c1157c) into master (9c42447) will increase coverage by 0.09%.
The diff coverage is 100.00%.

@@            Coverage Diff             @@
##           master      #50      +/-   ##
==========================================
+ Coverage   95.04%   95.14%   +0.09%     
==========================================
  Files           2        2              
  Lines         101      103       +2     
==========================================
+ Hits           96       98       +2     
  Misses          5        5              

Impacted Files	Coverage Δ
media_downloader.py	93.67% <100.00%> (+0.16%)	⬆️

---

Continue to review full report at Codecov.

Legend - Click here to learn more
Δ = absolute <relative> (impact), ø = not affected, ? = missing data
Powered by Codecov. Last update 9c42447...1c1157c. Read the comment docs.