Upstream commit 1fb90a7da186ee2ee098a666f6f3a35bb1720e59 added a
--disable-threads config option and changed the case to only match linux-gnu*
instead of linux*, because those are obviously very related changes.

This patch reverts that part of the commit, and fixes cross building to musl
archs for us.

diff --git a/configure b/configure
index 24b1cee..89a9937 100755
--- a/configure
+++ b/configure
@@ -17433,7 +17433,7 @@ if test x"$gl_use_threads" = xno; then
 $as_echo "$as_me: generated src/lock-obj-pub.native.h for $host" >&6;}
 elif test x$cross_compiling = xyes; then
   case $host in
-    *-*-linux-gnu*)
+    *-*-linux*)
     if test -n "$ac_tool_prefix"; then
   # Extract the first word of "${ac_tool_prefix}objdump", so it can be a program name with args.
 set dummy ${ac_tool_prefix}objdump; ac_word=$2
