SyncEvolution: use target-config@client-test-exchange for Client::Source
SyncEvolution: use target-config@client-test-exchange for Client::Source

SyncEvolution has changed how it finds config in the commit quoted
below. Adapted README accordingly.

commit 24efbe11dbae9394d4befb2b91a25cd403907ec2
Author: Patrick Ohly <patrick.ohly@intel.com>
Date:   Mon Aug 15 17:32:01 2011 +0200

    testing: use target-config@client-test-$CLIENT_TEST_SERVER for Client::Source

    For testing sources instantiated via SyncSource.cpp (for example, EDS)
    and client-test-app.cpp (ActiveSync) append the name of the server set
    via the CLIENT_TEST_SERVER env variable to target-config@client-test,
    separated by a hyphen.

    This allows configuring testing differently for different servers.
    Was already done for CalDAV sources, inside WebDAVSourceRegister.cpp.

simo5/evolution-activesync,simo5/evolution-activesync,simo5/evolution-activesync