fix tldr -u, use unzip -o to "overwrite existing files without prompting"

[flyxyz123]

after tldr -u, unzip without -o will prompt:

Archive:  /home/xyz/.cache//tldr/tldr.zip
replace /home/xyz/.cache//tldr/page-source/pages/android/settings.md? [y]es, [n]o, [A]ll, [N]one, [r]ename:
...

it requires user input to overwrite existing files
the prompt is hidden by silent, thus the script will show nothing and stop here

use -o to "overwrite existing files without prompting"

[flyxyz123]

for testing I use the following script to reproduce the bug, be careful this testing script will delete ~/test/tzip directory

#!/bin/sh

rm -rf ~/test/tzip/
mkdir -p ~/test/tzip/page-source/
curl -sfL https://github.com/tldr-pages/tldr-pages.github.io/raw/e7dd56b22b1a3ce7f3204565218357adc187c42a/assets/tldr.zip > ~/test/tzip/tldr_old.zip
curl -sfL https://raw.githubusercontent.com/tldr-pages/tldr-pages.github.io/master/assets/tldr.zip > ~/test/tzip/tldr.zip
unzip -d ~/test/tzip/page-source/ -u ~/test/tzip/tldr_old.zip 
echo 'without -o'
sleep 1
unzip -d ~/test/tzip/page-source/ -u ~/test/tzip/tldr.zip

[raylee]

Ah, of course. The way I use the script I hadn't hit this, and neglected to write a test around it. I'll add putting a test case for this on my todo list.

For now, this is great, thanks!