plugin: move definition for 'port' option to base plugin

Commit 7020491 ("esxi: add 'port' config parameter") started using
the 'port' option in a second plugin, but the definition stayed in the
PBS plugin. Avoid the hidden dependency and move the definition to the
base plugin instead.

It is necessary to mark it as optional or it would be required always.

Clarify that the option is not used by NFS and CIFS.

Signed-off-by: Fiona Ebner <f.ebner@proxmox.com>

src/PVE/Storage/PBSPlugin.pm

@@ -49,12 +49,6 @@ sub properties {
 	    description => "Base64-encoded, PEM-formatted public RSA key. Used to encrypt a copy of the encryption-key which will be added to each encrypted backup.",
 	    type => 'string',
 	},
-	port => {
-	    description => "For non default port.",
-	    type => 'integer',
-	    minimum => 1,
-	    maximum => 65535,
-	},
     };
 }
 

src/PVE/Storage/Plugin.pm

@@ -205,6 +205,15 @@ my $defaultData = {
 	    format => 'pve-storage-options',
 	    optional => 1,
 	},
+	port => {
+	    description => "Use this port to connect to the storage instead of the default one (for"
+		." example, with PBS or ESXi). For NFS and CIFS, use the 'options' option to"
+		." configure the port via the mount options.",
+	    type => 'integer',
+	    minimum => 1,
+	    maximum => 65535,
+	    optional => 1,
+	},
     },
 };