If a configuration for a peer is removed and then is recreated with one source,
all the sources reappear.  There seems to be no way to really remove a config
and start again from scratch.

To reproduce:

syncevolution --configure --template none backend=file database=file:///tmp/
databaseformat=text/calendar a@b s1
syncevolution --configure --template none backend=file database=file:///tmp/
databaseformat=text/calendar a@b s2
syncevolution --print-config a@b | grep ^\\[

syncevolution --remove a@b
syncevolution --configure --template none backend=file database=file:///tmp/
databaseformat=text/calendar a@b s1
syncevolution --print-config a@b | grep ^\\[

Both s1 and s2 appear in the final output, whereas only s1 should.  I haven't
checked but it may also be that attributes for the new s1 are defaulting to the
values of the old s1.