maybe fix japanese file read error

[chriddyp]

file.info returns file size in bytes

useBytes - logical: For readChar, should nchars be regarded as a
number of bytes not characters in a multi-byte locale?

This may fix an issue

In readChar(off, file.info(off)$size) :
can only read in bytes in a non-UTF-8 MBCS locale

from a user with a Japanese environment

[cpsievert]

The message below was automatically generated after build https://travis-ci.org/ropensci/plotly/builds/77362725

On TravisCI, commit 5a40038 was successfully merged with 3a6b9b4 (master) to create 99f3657. A visual testing table comparing 3a6b9b4 with 99f3657 can be found here ->

http://cpsievert.github.io/plotly-test-table/R/99f3657/

Detected 0 differences

[cpsievert]

@chriddyp seems reasonable, and works on my system, so +1.

While checking this out locally I discovered a separate bug in creating offline plots from my terminal -- 4969d70 fixes it.

[cpsievert]

The message below was automatically generated after build https://travis-ci.org/ropensci/plotly/builds/77395647

On TravisCI, commit 4969d70 was successfully merged with 3a6b9b4 (master) to create dc10b28. A visual testing table comparing 3a6b9b4 with dc10b28 can be found here ->

http://cpsievert.github.io/plotly-test-table/R/dc10b28/

Detected 0 differences

[chriddyp]

confirmed by user that this fixed the issue 😅

[cpsievert]

nice, great work @chriddyp!