ci: Bump number of failing spectests to 3

The upstream fix for newly discovered spectests issue is in
WebAssembly/spec#1251.

Author: chfast

circle.yml

@@ -208,10 +208,10 @@ commands:
         default: false
       expected_passed:
         type: integer
-        default: 18900
+        default: 18899
       expected_failed:
         type: integer
-        default: 2
+        default: 3
       expected_skipped:
         type: integer
         default: 477