Use https prefix for mirror and remove TE

Change-Id: I21b31bdafb0a22ab4cccb7e71cead8a50a0daade
diff --git a/_data/mirrors.yml b/_data/mirrors.yml
index 4cda200..238ebdd 100644
--- a/_data/mirrors.yml
+++ b/_data/mirrors.yml
@@ -1,6 +1,2 @@
 - description: Primary (Recommended)
-  baseurl: http://dl.twrp.me/
-
-- description: Techerrata in Germany (may be out of date)
-  baseurl: http://techerrata.com/browse/twrp2/
-
+  baseurl: https://dl.twrp.me/