[epiphany] Update gvdb README.epiphany to include clang static analyzer changes

[Michael Catanzaro <mcatanzaro src gnome org>]

commit 1981b137db189862aca472269036ab3e6136f451
Author: Jan-Michael Brummer <jan brummer tabos org>
Date:   Tue Jan 7 13:51:41 2020 +0100

    Update gvdb README.epiphany to include clang static analyzer changes

 lib/contrib/gvdb/README.epiphany | 3 +++
 1 file changed, 3 insertions(+)
---
diff --git a/lib/contrib/gvdb/README.epiphany b/lib/contrib/gvdb/README.epiphany
index bda8c72ac..32f36f50a 100644
--- a/lib/contrib/gvdb/README.epiphany
+++ b/lib/contrib/gvdb/README.epiphany
@@ -3,3 +3,6 @@ GVariant Database
  * Copied from https://git.gnome.org/browse/gvdb commit a6f0eadb51aae5351a0cfd6b9da3dcba6b134e1a
  * Removed G_GNUC_INTERNAL and GVDB_GNUC_WEAK
  * Fix -Wsign-compare
+ * Add clang ifdef guards (#ifndef __clang_analyzer__) around:
+   - file_builder_allocate_for_hash
+   - file_builder_add_hash