Add clear instructions to new wallet dialog when choosing GPG

Issue being addressed KDE Bug 353960 First reported 2015-10-16, confirmed in the current kwallet. When users enter passwords in KDE (i.e. for WiFi) and are prompted to set up a new wallet using KWallet storage of the passwords, they are presented with two options, Blowfish or GPG, and are informed GPG is the better option. Subsequent to selecting GPG, on a new installation of an OS, they are immediately presented with an error message that does not clearly explain the possible solutions (as is evidenced by the comments spanning 9 years in the bug report). It is likely many new users of Linux & KDE resort to Blowfish or assume continually cancel out of KWallet / attempt to remove KWallet (I've done both of over the past 9 years).

Proposed Code Change This merge request is for a change in knewwalletdialog.cpp, to change the message displayed in KWallet when users have newly installed their OS and select GPG from "Seems that your system has no keys suitable for encryption. Please set-up at " "least one encryption key, then try again." to "No suitable keys for encryption found. To create a GPG key, you can:\n" "1. Option 1) Open Kleopatra and follow Kleopatra's documentation at: https://docs.kde.org/stable5/en/kleopatra/kleopatra/functions-newkey.html\n" "2. Option 2) Open Konsole and enter the command: gpg --full-gen-key, then follow the instructions."