libmicrohttpd: Add CPE string.

This helps in CVE tracking.

BUG=None
TEST=PreCQ passes

Change-Id: I7c52be0b844aa01247ec6ce4b6704f033ddc937a
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/overlays/portage-stable/+/1865028
Tested-by: Allen Webb <allenwebb@google.com>
Reviewed-by: Luum Habtemariam <luum@chromium.org>
Reviewed-by: Mike Frysinger <vapier@chromium.org>
Commit-Queue: Allen Webb <allenwebb@google.com>
diff --git a/net-libs/libmicrohttpd/metadata.xml b/net-libs/libmicrohttpd/metadata.xml
index e486bb8..4c81eed 100644
--- a/net-libs/libmicrohttpd/metadata.xml
+++ b/net-libs/libmicrohttpd/metadata.xml
@@ -9,5 +9,8 @@
 		<flag name='messages'>enable error messages</flag>
 		<flag name='epoll'>use epoll() system call</flag>
 	</use>
+	<upstream>
+		<remote-id type="cpe">cpe:/a:gnu:libmicrohttpd</remote-id>
+	</upstream>
 </pkgmetadata>