File add-guile-3.0-support.patch of Package guile-charting

--- configure.ac.orig	2020-01-20 16:16:14.113994591 +0100
+++ configure.ac	2020-01-20 16:16:23.418176060 +0100
@@ -25,7 +25,7 @@
 AM_INIT_AUTOMAKE([-Wall -Wno-portability])
 AM_SILENT_RULES([yes])
 
-GUILE_PKG([2.2 2.0])
+GUILE_PKG([3.0 2.2 2.0])
 GUILE_PROGS
 PKG_CHECK_MODULES(GUILE_CAIRO, guile-cairo)