Update util.jl

Author: DilumAluthge

test/util.jl

@@ -2,11 +2,14 @@ extract_test_result_value(test_result::Test.Pass) = test_result.value
 
 recursively_unwrap_ex(ex::ErrorException) = ex
 recursively_unwrap_ex(ex::Base.IOError) = ex
-function recursively_unwrap_ex(outer_ex::TaskFailedException)
-  new_thing = outer_ex.task.exception
-  return recursively_unwrap_ex(new_thing)
-end
 
+@static if Base.VERSION >= v"1.2-"
+  function recursively_unwrap_ex(outer_ex::TaskFailedException)
+    new_thing = outer_ex.task.exception
+    return recursively_unwrap_ex(new_thing)
+  end
+end
+  
 Base.@kwdef struct ConfigForTestingTaskFailedException
   expected_outer_ex_T
   expected_inner_ex_INSTANCE