fixes blank server-tether property in profile.xml

I think we want 'force': True.

[10/30/14, 4:35:43 PM] Danny Roberts: from https://bitbucket.org/commcare/commcare/wiki/CommCareProfile, it looks like force="true" in

<property key="server-tether" value="sync" force="true"/>

would make it so that anyone who receives the update on their phone will have the setting overridden to this new default
[10/30/14, 4:36:00 PM] Danny Roberts: whereas force="false" means only change this setting on a clean install
[10/30/14, 4:36:03 PM] Danny Roberts: is that right?
[10/30/14, 4:42:27 PM] Danny Roberts: (this is about the p2 bug)
[10/30/14, 4:43:19 PM] Clayton Sims: Truth
[10/30/14, 4:43:34 PM] Danny Roberts: so then we want it set to force="true", right?
[10/30/14, 4:44:56 PM] Clayton Sims: yes
[10/30/14, 4:45:18 PM] Danny Roberts: only in the case of case sharing being turned on
[10/30/14, 4:45:25 PM] Danny Roberts: (that's the only place the bug affected)