Revert change to src/util.cpp affected by merge (#958), which removed 'support for -zcashparamsdir parameter'

[mattmill30]

'support for -zcashparamsdir parameter' was committed to src/util.cpp in the miketout/VerusCoin repository by @miketout on Oct 24, 2018 - miketout@8a1e0d0 - and then with his commit 'Integrate latest Zcash fixes and update for non-latin user names' - miketout@99aeab2 - for no apparent reason immediately removed the feature, before creating pull request #958.

This feature has subsequently been added to the upstream zcash repository as 'Allow configure params directory' on Aug 7, 2020 so the feature is clearly not deprecated.
zcash@3b5966e

I think the -zcashparamsdir parameter is more appropriate for separate projects which share the common params with zcash as it distinguishes enhancements and feature sets created by first and third parties, but either way, please reintroduce this parameter either by reverting 99aeab2#diff-449acf764318b0ca96972daf8d28a28af79ad2c3381044851f2953792fcd8eef or merging the upstream -paramsdir parameter - zcash@3b5966e.