Fix duplicate "df-" in "df-df-manual"

Author: owen-mc

java/ql/lib/ext/javax.crypto.model.yml

@@ -24,5 +24,5 @@ extensions:
       - ["javax.crypto", "Cipher", "update", "", "summary", "df-manual"]
       - ["javax.crypto", "Cipher", "updateAAD", "", "summary", "df-manual"]
       - ["javax.crypto", "Cipher", "wrap", "", "summary", "df-manual"]
-      - ["javax.crypto", "Mac", "init", "(Key)", "summary", "df-df-manual"]
-      - ["javax.crypto", "Mac", "doFinal", "()", "summary", "df-df-manual"]
+      - ["javax.crypto", "Mac", "init", "(Key)", "summary", "df-manual"]
+      - ["javax.crypto", "Mac", "doFinal", "()", "summary", "df-manual"]