update git URLs (git -> https; gitea)

Change-Id: I9b41e0b88785d34809db0e62e82aaa71f8127f71
diff --git a/debian/copyright b/debian/copyright
index 41573fe..e705c87 100644
--- a/debian/copyright
+++ b/debian/copyright
@@ -1,6 +1,6 @@
 Format: http://www.debian.org/doc/packaging-manuals/copyright-format/1.0/
 Upstream-Name: libosmo-abis
-Source: git://git.osmocom.org/libosmo-abis.git
+Source: https://gitea.osmocom.org/osmocom/libosmo-abis
 
 Files: *
 Copyright: 2008      Daniel Willmann <daniel@totalueberwachung.de>