Dont down an interface during ifreload just because the number of iface

sections for that interface changed

Ticket: CM-5841
Reviewed By:
Testing Done: tested ifreload with new iface section

<email_notes>
problem stmt:
if the user adds a new section for an existing interface, I mark the
interface for down.
Basically the below:

               if len(newifaceobjlist) != len(lastifaceobjlist):
                    ifacedownlist.append(ifname)
                    continue

You rarely need to add a new section to the interfaces file. It is not
recommended even by the user guide.
sankaran was trying to add a new address. Which he could have added to
the same iface section.

But, looking at his trivial example, i am thinking of not marking an
interface for down if the user merely tried to add a new section to an
existing interface
</email_notes>

ifupdown/ifupdownmain.py

@@ -1188,11 +1188,11 @@ class ifupdownMain(ifupdownBase):
                 if not newifaceobjlist:
                     ifacedownlist.append(ifname)
                     continue
+                if not down_changed:
+                    continue
                 if len(newifaceobjlist) != len(lastifaceobjlist):
                     ifacedownlist.append(ifname)
                     continue
-                if not down_changed:
-                    continue
 
                 # If interface has changed between the current file
                 # and the last installed append it to the down list