Enable produce.offset.report by default (#266)

[edenhill]

Without this enabled:

% Message delivered to test [0] @ 0
% Message delivered to test [0] @ 0
% Message delivered to test [0] @ 0
% Message delivered to test [0] @ 0
% Message delivered to test [0] @ 0
% Message delivered to test [0] @ 0
% Message delivered to test [0] @ 0
% Message delivered to test [0] @ 0
% Message delivered to test [0] @ 0
% Message delivered to test [0] @ 0
% Message delivered to test [0] @ 0
% Message delivered to test [0] @ 0
% Message delivered to test [0] @ 113

With this enabled:

% Message delivered to test [0] @ 157
% Message delivered to test [0] @ 160
% Message delivered to test [0] @ 161
% Message delivered to test [0] @ 162
% Message delivered to test [0] @ 163
% Message delivered to test [0] @ 164
% Message delivered to test [0] @ 165
% Message delivered to test [0] @ 166
% Message delivered to test [0] @ 167
% Message delivered to test [0] @ 170
% Message delivered to test [0] @ 171
% Message delivered to test [0] @ 172
% Message delivered to test [0] @ 173
% Message delivered to test [0] @ 174
% Message delivered to test [0] @ 175
% Message delivered to test [0] @ 176
% Message delivered to test [0] @ 177
% Message delivered to test [0] @ 200