Fixing a gpg rvm.io install step with input from a newcomer (publicla…

…b#10041)

Apparently the old version of this line didn't work - and https://RVM.io has updated it... should we make this change? does it work for others?

README.md

@@ -133,7 +133,7 @@ Before continuing with the installation steps in this README, users of Windows S
   * `sudo apt install libyaml-dev make pkg-config sqlite3 zlib1g-dev libgmp-dev`
   * `sudo apt install libreadline-dev libssl-dev`
 2. Add GPG Key & Install RVM:
-  * `gpg --keyserver hkp://keys.gnupg.net --recv-keys 409B6B1796C275462A1703113804BB82D39DC0E37D2BAF1CF37B13E2069D6956105BD0E739499BDB`
+  * `gpg2 --recv-keys 409B6B1796C275462A1703113804BB82D39DC0E3 7D2BAF1CF37B13E2069D6956105BD0E739499BDB`
   * `curl -sSL https://get.rvm.io | bash -s stable`
 3. Load the Script environment variables using source command:
   * `source ~/.rvm/scripts/rvm`