it will print some wrong stack when use pr_stacktrace() with unicode thing

[zsbxp]

try
throw("测试")
catch
Class:Reason ->
lager:info("get_stacktrace:ntp", [lager:pr_stacktrace(erlang:get_stacktrace(), {Class, Reason})])
end.

In our system, the exception will throw with some Chinese word sometimes.
If that happen, it will print like this:
lager_trunc_io:print/3 line 269
lager_trunc_io:list_body/4 line 312
lager_trunc_io:list_bodyc/4 line 324
lager_trunc_io:list_bodyc/4 line 323
lager_trunc_io:print/3 line 168
lager_trunc_io:alist/3 line 421
lager_trunc_io:alist/3 line 421
lager_trunc_io:alist/3 line 448

and can not get back the stack really happened