patch 8.2.3022: available encryption methods are not strong enough

Problem:    Available encryption methods are not strong enough.
Solution:   Add initial support for xchaha20. (Christian Brabandt,
            closes #8394)
diff --git a/src/config.h.in b/src/config.h.in
index fbf4b24..0808cc3 100644
--- a/src/config.h.in
+++ b/src/config.h.in
@@ -208,6 +208,7 @@
 #undef HAVE_STRPTIME
 #undef HAVE_STRTOL
 #undef HAVE_CANBERRA
+#undef HAVE_SODIUM
 #undef HAVE_ST_BLKSIZE
 #undef HAVE_SYSCONF
 #undef HAVE_SYSCTL