configure: Fix printing of commands from run

The `run` function passed its argument to `msg` via `"$@"`, but `msg`
only printed its first argument. I think the intention was for `msg` to
print all its arguments. (If not, `run` should only `msg "$1"`.)

configure

@@ -1,7 +1,7 @@
 #!/bin/sh
 
 msg() {
-    echo "configure: $1"
+    echo "configure: $*"
 }
 
 step_msg() {