Fix xquartz link

bkmgit · web-flow · commit 9e74efe5a3b9 · 2021-04-18T10:19:47.000+03:00
addresses hpc-carpentry#21
diff --git a/setup.md b/setup.md
@@ -126,7 +126,7 @@ macOS comes with SSH pre-installed: you do not have to do anything.
 > ## GUI Support
 >
 > If you know that the software you will be running requires a graphical user
-> interface, please install [XQuartz](www.xquartz.org).
+> interface, please install [XQuartz](https://www.xquartz.org).
 {: .discussion}
 
 ### Linux

Original file line number	Diff line number	Diff line change
`@@ -126,7 +126,7 @@ macOS comes with SSH pre-installed: you do not have to do anything.`
`126`	`126`	`> ## GUI Support`
`127`	`127`	`>`
`128`	`128`	`> If you know that the software you will be running requires a graphical user`
`129`		`-> interface, please install [XQuartz](www.xquartz.org).`
	`129`	`+> interface, please install [XQuartz](https://www.xquartz.org).`
`130`	`130`	`{: .discussion}`
`131`	`131`
`132`	`132`	`### Linux`