Bug 1579088 - Correct the expecting result for img in test_strict_dynamic_default_src.html; r=ckerschb

The description and expected result of some tests aren't matched.

Differential Revision: https://phabricator.services.mozilla.com/D44843

--HG--
extra : moz-landing-system : lando

dom/security/test/csp/test_strict_dynamic_default_src.html

@@ -66,14 +66,14 @@ var tests = [
     script_desc: "(test 6) script should be allowed because of valid nonce",
     img_desc: "(test 6) img should be blocked because of default-src http:",
     script_result: "blocked",
-    img_result: "allowed",
+    img_result: "blocked",
     policy: "script-src 'nonce-bar' http:; default-src 'strict-dynamic' http:;"
   },
   {
     script_desc: "(test 7) script should be allowed because of invalid nonce",
     img_desc: "(test 7) img should be blocked because of image-src http:",
     script_result: "blocked",
-    img_result: "allowed",
+    img_result: "blocked",
     policy: "script-src 'nonce-bar' http:; default-src 'strict-dynamic' http:; img-src http:"
   },
 ];