Merge pull request #1780 from nabinhait/v4-hotfix

minor fix in global defaults
Reload sales taxes and charges in patch
Show website route for generator via set_intro, fix in Support Email Settings
Merge pull request #1781 from anandpdoshi/hotfix

Reload sales taxes and charges in patch
Minor fix in newsletter
Fixed Recurring Sales Invoice
Update CONTRIBUTING.md
Minor fixes in salary manager. Fixes #1754