Make default distribution U10 for deb template

Change-Id: Ifcfc7d1fbb6fac2a785a0dc5a4e6ba09cf898ed4
Signed-off-by: Jeff Peeler <jpeeler@redhat.com>

templates/WordPress_Single_Instance_deb.template

@@ -61,7 +61,7 @@
       "ConstraintDescription" : "must contain only alphanumeric characters."
     },
     "LinuxDistribution": {
-      "Default": "F17",
+      "Default": "U10",
       "Description" : "Distribution of choice",
       "Type": "String",
       "AllowedValues" : "U10"