build: point musl build hint at sr.ht jerboa/vendor/ChezScheme

ober

d9f70b7ccec5b4c2134cf0c7607b9343493553bd

diff --git a/build-gitsafe-musl.ss b/build-gitsafe-musl.ss
index b90b0ad..d12ec6c 100644
--- a/build-gitsafe-musl.ss
+++ b/build-gitsafe-musl.ss
@@ -29,7 +29,7 @@
 (unless musl-chez-prefix
   (display "Error: Cannot find musl Chez install.\n")
   (display "  Set JERBOA_MUSL_CHEZ_PREFIX or install to ~/chez-musl\n")
-  (display "  See: https://github.com/ober/ChezScheme (build with --static CC=musl-gcc)\n")
+  (display "  See: https://git.sr.ht/~lisp/jerboa (vendor/ChezScheme — build with --static CC=musl-gcc)\n")
   (exit 1))
 
 (define musl-chez-dir