`rstudio$.rs.isDesktop()` fails on very old versions of RStudio

[guslipkin]

I am using a very old environment that cannot be upgraded to a newer version of RStudio. Some other packages I'm using use the rstudioapi package which attempts to reference rstudio$.rs.isDesktop() which is not available in that old version of RStudio. I believe the minimum version argument should be passed to verifyAvailable() to ensure the function is available.

rstudioapi/R/code.R

Lines 91 to 93 in 15347e9

	verifyAvailable()
	rstudio <- as.environment("tools:rstudio")
	if (rstudio$.rs.isDesktop()) "desktop" else "server"

[kevinushey]

Thanks; I'll take a look.