docs: small typo in formatdomain.html

docs/formatdomain.html.in

@@ -2458,7 +2458,7 @@
       is directly assigned to the guest using generic device
       passthrough, after first optionally setting the device's MAC
       address to the configured value, and associating the device with
-      an 802.1Qgh capable switch using an optionally specified
+      an 802.1Qbh capable switch using an optionally specified
       <virtualport> element (see the examples of virtualport
       given above for type='direct' network devices). Note that - due
       to limitations in standard single-port PCI ethernet card driver