get_profile() - handle new OpenSSH DSA key format

OpenSSH changed the format of the DSA key, and this broke Sugar
connection to Jabber.

Fixes https://github.com/sugarlabs/sugar/issues/814

Fixes http://bugs.sugarlabs.org/ticket/4992

src/sugar3/profile.py

@@ -115,10 +115,12 @@ class Profile(object):
         end_found = False
         for l in lines:
             l = l.strip()
-            if l.startswith('-----BEGIN DSA PRIVATE KEY-----'):
+            if l.startswith(['-----BEGIN DSA PRIVATE KEY-----',
+                             '-----BEGIN OPENSSH PRIVATE KEY-----']):
                 begin_found = True
                 continue
-            if l.startswith('-----END DSA PRIVATE KEY-----'):
+            if l.startswith(['-----END DSA PRIVATE KEY-----',
+                             '-----END OPENSSH PRIVATE KEY-----']):
                 end_found = True
                 continue
             key += l