Disable vim-EnhancedJumps key mappings using the new option available for just that

[pacha]

Currently Vem disables vim-EnhancedJumps key mappings by creating fake ones. Now there's a g:EnhancedJumps_no_mappings configuration option to do so since inkarkat/vim-EnhancedJumps@94ec8d50d97119d9f526c61f9a35c26563d1ef45. Would be nice to use that instead of doing the hackish remapping.