add patch to set USE_SLASH_PROC macro

This adds a fix to use functions from procps to determine routing information. I thought this was fixed with open-vm-tools-9.4.6-1770165-0002-configure-Fix-USE_SLASH_PROC-conditional.patch , but that alone was not enough.

The issue can be verified with the command on the ESXi console (or with Workstation/Fusion with vmware-vim-cmd if the vm is shared):
vim-cmd  vmsvc/get.guest <id>

This should not be empty, and actually show the routing table:

         ipRouteConfig = (vim.net.IpRouteConfigInfo) {
            ipRoute = (vim.net.IpRouteConfigInfo.IpRoute) [
               (vim.net.IpRouteConfigInfo.IpRoute) {
                  network = "0.0.0.0", 
                  prefixLength = 0, 
                  gateway = (vim.net.IpRouteConfigInfo.Gateway) {
                     ipAddress = "10.20.95.253", 
                     device = "0"
                  }
               }, 
...