gnu: Set license of the bootstrap tools.

* gnu/packages/bootstrap.scm (package-from-tarball)[license]: Set to
  GPL3+.
* gnu/packages/make-bootstrap.scm (%static-binaries)[license]:
  Likewise.

gnu/packages/bootstrap.scm

@@ -127,7 +127,7 @@ successful, or false to signal an error."
     (synopsis description)
     (description #f)
     (home-page #f)
-    (license #f)))
+    (license gpl3+)))
 
 (define package-with-bootstrap-guile
   (memoize

gnu/packages/make-bootstrap.scm

@@ -271,7 +271,7 @@ for `sh' in $PATH, and without nscd, and with static NSS modules."
     (synopsis "Statically-linked bootstrap binaries")
     (description
      "Binaries used to bootstrap the distribution.")
-    (license #f)
+    (license gpl3+)
     (home-page #f)))
 
 (define %binutils-static