Bump up suffix version to include latest patches

Author: Akendo

prepare_source

@@ -3,4 +3,4 @@ version="$version_orig-1"
 git_src --branch "debian/openssl-$version" "https://salsa.debian.org/debian/openssl.git"
 import_upstream_patches
 apply_patches patches-debian
-version_suffix="gl13~bp1877"
+version_suffix="gl15~bp1877"