Check dependencies to avoid a useless sudo on Archlinux

[Ealrann]

Purpose:

Prevent a useless call to sudo during this installation of Chia on Archlinux, by checking if the dependencies are not already installed.
The point is to make the installation easier:

• sudo forces the user to type its password (event if there is nothing to do).
• Some people prefer to use su and don't setup sudo. In this case, the installation of chia is impossible without modifying the instal.sh. (it's what I do for years)

Old Behavior:

Calling sudo every time to install the dependencies.

New Behavior:

Verify if git and openssl are installed, then call sudo pacman -S git openssl only if needed.

Testing Notes:

I wanted to keep the existing code, so I simply added a if statement. But in fact, we can simplify the code for Archlinux:
no dependencies needs to be installed (at least line 213), because:

• openssl is a base package of archlinux (base => coreutils => openssl)
• git is already called line 71 (so no point to install it line 213, it's too late).

[hoffmang9]

Thanks for this. Can you sign your commit or open a new PR with a signed commit to start it?

[Ealrann]

Oh sorry, I've just corrected it

[coveralls-official]

Pull Request Test Coverage Report for Build 7305042311

• 0 of 0 changed or added relevant lines in 0 files are covered.
• 35 unchanged lines in 9 files lost coverage.
• Overall coverage decreased (-0.03%) to 90.55%

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Files with Coverage Reduction	New Missed Lines	%
chia/rpc/rpc_server.py	1	88.4%
chia/rpc/wallet_rpc_api.py	1	88.09%
tests/core/util/test_lockfile.py	1	91.09%
chia/timelord/timelord_launcher.py	2	69.77%
chia/wallet/wallet_node.py	2	88.31%
chia/server/node_discovery.py	3	78.35%
chia/full_node/full_node_api.py	4	77.93%
chia/full_node/full_node.py	8	84.38%
chia/timelord/timelord.py	13	79.0%

Totals
Change from base Build 7304634562:	-0.03%
Covered Lines:	94019
Relevant Lines:	103797

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💛 - Coveralls

[hoffmang9]

lgtm with thannks!