Add CPE for curl.

Fixes: 194342713
Change-Id: I0fe27035371fd6125befe7709320df25fccaa799
Test: no tests, just updating metadata about source code
diff --git a/METADATA b/METADATA
index 0ef3121..d23bce3 100644
--- a/METADATA
+++ b/METADATA
@@ -16,4 +16,7 @@
     month: 8
     day: 10
   }
+  security {
+    tag: "NVD-CPE2.3:cpe:/a:haxx:curl:7.78.0"
+  }
 }