[Tools] testbot: Improve the $VM::GetHost() documentation.

[Francois Gouget]

Signed-off-by: Francois Gouget 
---
 testbot/lib/WineTestBot/VMs.pm | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/testbot/lib/WineTestBot/VMs.pm b/testbot/lib/WineTestBot/VMs.pm
index 7bd6d64b..b9313429 100644
--- a/testbot/lib/WineTestBot/VMs.pm
+++ b/testbot/lib/WineTestBot/VMs.pm
@@ -179,7 +179,9 @@ sub GetHost($)
 {
   my ($self) = @_;

-  # The URI is of the form protocol://user@hostname/hypervisor-specific-data
+  # VirtURI is of the form proto://user@hostname:port/hypervisor-specific-data
+  # This returns the 'hostname:port' part. Note that the port can be used to
+  # tunnel connections to different VM hosts and thus must be included.
   return $1 if ($self->VirtURI =~ m%^[^:]+://(?:[^/@]*@)?([^/]+)/%);
   return "localhost";
 }