Add a reduced test-case for issue 7696

Issue 7696 was one of the issues fixed by PR 8580. The other ones were all cases of missing glyphs, however in this particular one glyphs did render but every single one was incorrect.
Hence it probably cannot hurt to have a small, reduced, reference test for that PDF file as well.

test/pdfs/.gitignore

@@ -43,6 +43,7 @@
 !issue7580.pdf
 !issue7598.pdf
 !issue7665.pdf
+!issue7696.pdf
 !issue7835.pdf
 !issue7855.pdf
 !issue7872.pdf

test/test_manifest.json

@@ -1163,6 +1163,13 @@
        "link": false,
        "type": "eq"
     },
+    {  "id": "issue7696",
+       "file": "pdfs/issue7696.pdf",
+       "md5": "0593f52d03251164caa219d704a15e4c",
+       "rounds": 1,
+       "link": false,
+       "type": "eq"
+    },
     {  "id": "tutorial",
        "file": "pdfs/tutorial.pdf",
        "md5": "6e122f618c27f3aa9a689423e3be6b8d",