Switch to toybox getconf(1).

Test: treehugger
Change-Id: I7b43673b6a349116dd3e100f5e7eef704244e7ef
diff --git a/ui/build/paths/config.go b/ui/build/paths/config.go
index e306929..adcc766 100644
--- a/ui/build/paths/config.go
+++ b/ui/build/paths/config.go
@@ -85,7 +85,6 @@
 	"egrep":     Allowed,
 	"find":      Allowed,
 	"fuser":     Allowed,
-	"getconf":   Allowed,
 	"getopt":    Allowed,
 	"git":       Allowed,
 	"grep":      Allowed,
@@ -157,6 +156,7 @@
 	"env":      Toybox,
 	"expr":     Toybox,
 	"head":     Toybox,
+	"getconf":  Toybox,
 	"id":       Toybox,
 	"ln":       Toybox,
 	"ls":       Toybox,