xenserver: Delete Bridge when creating vlan.
xenserver: Delete Bridge when creating vlan.

Commit 34edeccfd8d4273844d12c85fe38ec47002c47cd removed a
workaround which still applies to XenServer versions older than
5.5.  This could causes creation of vlans to fail in some cases.

CC: "David Tsai" <dtsai@nicira.com>
Bug #4877.

Signed-off-by: Dominic Curran <e7acd2a42b8d40d54891617f0fcb6b34b4433eaa@citrix.com>

salvocambria/xen-api,djs55/xen-api,thomassa/xen-api,vasilenkomike/xen-api,cheng-z/xen-api,djs55/xen-api,anoobs/xen-api,thomassa/xen-api,jjd27/xen-api,anoobs/xen-api,euanh/xen-api,cheng--zhang/xen-api,guard163/xen-api,djs55/xen-api,robertbreker/xen-api,agimofcarmen/xen-api,guard163/xen-api,euanh/xen-api,cheng-z/xen-api,srowe/xen-api,cheng--zhang/xen-api,koushikcgit/xen-api,ravippandey/xen-api,agimofcarmen/xen-api,cheng-z/xen-api,salvocambria/xen-api,euanh/xen-api,anoobs/xen-api,vasilenkomike/xen-api,euanh/xen-api,anoobs/xen-api,ravippandey/xen-api,koushikcgit/xen-api,robertbreker/xen-api,ravippandey/xen-api,cheng--zhang/xen-api,Frezzle/xen-api,vasilenkomike/xen-api,rafalmiel/xen-api,cheng--zhang/xen-api,vasilenkomike/xen-api,jjd27/xen-api,srowe/xen-api,simonjbeaumont/xen-api,Frezzle/xen-api,jjd27/xen-api,guard163/xen-api,cheng--zhang/xen-api,koushikcgit/xen-api,rafalmiel/xen-api,ravippandey/xen-api,simonjbeaumont/xen-api,srowe/xen-api,agimofcarmen/xen-api,djs55/xen-api,simonjbeaumont/xen-api,Frezzle/xen-api,huizh/xen-api,thomassa/xen-api,anoobs/xen-api,thomassa/xen-api,koushikcgit/xen-api,robertbreker/xen-api,cheng-z/xen-api,djs55/xen-api,koushikcgit/xen-api,thomassa/xen-api,jjd27/xen-api,srowe/xen-api,agimofcarmen/xen-api,cheng-z/xen-api,robertbreker/xen-api,Frezzle/xen-api,simonjbeaumont/xen-api,koushikcgit/xen-api,huizh/xen-api,guard163/xen-api,salvocambria/xen-api,agimofcarmen/xen-api,ravippandey/xen-api,huizh/xen-api,rafalmiel/xen-api,robertbreker/xen-api,salvocambria/xen-api,salvocambria/xen-api,vasilenkomike/xen-api,huizh/xen-api,cheng-z/xen-api,cheng-z/xen-api,djs55/xen-api,simonjbeaumont/xen-api,guard163/xen-api,srowe/xen-api,huizh/xen-api,simonjbeaumont/xen-api,anoobs/xen-api,jjd27/xen-api,ravippandey/xen-api,agimofcarmen/xen-api,robertbreker/xen-api,vasilenkomike/xen-api,cheng--zhang/xen-api,rafalmiel/xen-api,rafalmiel/xen-api,guard163/xen-api,euanh/xen-api,Frezzle/xen-api,rafalmiel/xen-api,thomassa/xen-api,huizh/xen-api,jjd27/xen-api,cheng--zhang/xen-api,salvocambria/xen-api,euanh/xen-api