ESX test case needs '/' in interface name

To fix an ESX test case, valid interface names need '/' as valid letter.
Signed-off-by: NStefan Berger <stefanb@us.ibm.com>

src/conf/domain_conf.h

@@ -298,7 +298,7 @@ struct _virDomainNetDef {
 };
 
 # define VALID_IFNAME_CHARS \
- "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789-_"
+ "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789-_/"
 
 enum virDomainChrTargetType {
     VIR_DOMAIN_CHR_TARGET_TYPE_NULL = 0,