duplicated version information in the startup message

[ShuguangSun]

R version 3.5.2 (2/15/2019 1:42:58 AM-2/15/2019 1:42:58 AM-2/15/2019 1:42:58 AM) -- "Eggshell Igloo"

It has three times of "2/15/2019 1:42:58 AM"

[thequackdaddy]

Yeah I've seen that in the past.

I probably should read more about how R for Windows reports its versions and where it is tied into the build.

R is developed using SVN and I think the version numbering is tied to that somehow. So here I do a pretty hacky workaround to fill out the version number.

I would guess this might work better if I used R's official SVN instead of a very much un-official mirror on GitHub. I do know that R SVN is very slow to mirror--at least for me on my Internet connection. Appveyor might be faster.