Added better check if nfs server is available on SUSE hosts

plugins/hosts/suse/cap/nfs.rb

@@ -2,6 +2,10 @@ module VagrantPlugins
   module HostSUSE
     module Cap
       class NFS
+        def self.nfs_installed(env)
+          system("rpm -q nfs-kernel-server > /dev/null 2>&1")
+        end
+
         def self.nfs_check_command(env)
           "pidof nfsd > /dev/null"
         end

plugins/hosts/suse/plugin.rb

@@ -11,6 +11,11 @@ module VagrantPlugins
         Host
       end
 
+      host_capability("suse", "nfs_installed") do
+        require_relative "cap/nfs"
+        Cap::NFS
+      end
+
       host_capability("suse", "nfs_check_command") do
         require_relative "cap/nfs"
         Cap::NFS