oauth2: Add Strava to list of broken oauth2 endpoints

Fixes #101

Change-Id: I26b460dd0261c9599b2917ff97fa4f0c13218a3e
Reviewed-on: https://go-review.googlesource.com/7850
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
diff --git a/oauth2.go b/oauth2.go
index f799eda..dae0066 100644
--- a/oauth2.go
+++ b/oauth2.go
@@ -430,6 +430,7 @@
 	"https://api.pushbullet.com/",
 	"https://oauth.sandbox.trainingpeaks.com/",
 	"https://oauth.trainingpeaks.com/",
+	"https://www.strava.com/oauth/",
 }
 
 // providerAuthHeaderWorks reports whether the OAuth2 server identified by the tokenURL