Upgrade to Electrum version

[KevinMellott91]

Are there plans to upgrade the version of Electrum to 3.0.5 or newer? That team has documented a major security vulnerability that was introduced in v2.6 and fixed with v3.0.5; however, I realize that this project is using v2.4.1 and is therefore not affected.

However, there have probably been a number of improvements and enhancements since the 2.4.1 version that would benefit the wallet. Current version being used is 2.5 yrs old at this point.

https://github.com/spesmilo/electrum-docs/blob/master/cve.rst