Fix issue with project avatar not being returned by project endpoint when reading; ensure only set during update

bitbucket/resource_project_test.go

@@ -15,6 +15,8 @@ func TestAccBitbucketProject(t *testing.T) {
 		resource "bitbucketserver_project" "test" {
 			key = "TEST%v"
 			name = "test-repo-for-repository-test"
+			description = "My description"
+			avatar = "data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAAEAAAABCAYAAAAfFcSJAAAADUlEQVR42mP8z/C/HgAGgwJ/lK3Q6wAAAABJRU5ErkJggg=="
 		}
 	`, rand.New(rand.NewSource(time.Now().UnixNano())).Int())