Revert the http_rev back to 7d2d87e

The recent http roll may have broken an internal test.

This partially reverts 313fd86, https://dart-review.googlesource.com/c/sdk/+/439804

Change-Id: I8d1dc261f8a18f4306559546efe134c078693b74
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/440262
Reviewed-by: Devon Carew <[email protected]>
Commit-Queue: Brian Quinlan <[email protected]>
Reviewed-by: Brian Quinlan <[email protected]>

Author: srawlins

DEPS

@@ -136,7 +136,7 @@ vars = {
   "dartdoc_rev": "882aea9351262d618c955322f4c9aafe9540b848",
   "ecosystem_rev": "d5233c6dd0767cffa5742e32c4bc7c230c9c4b12",
   "flute_rev": "e4ea0459a7debae5e9592c85141707b01fac86c9",
-  "http_rev": "4209e846100cb22d60dea7e48727334b8c55be34",
+  "http_rev": "7d2d87ebfba86035a9ca6b79160ccc2ac1253c0c",
   "i18n_rev": "c45e050426bdeaaa120e5ce856abb486863d0476",
   "leak_tracker_rev": "f5620600a5ce1c44f65ddaa02001e200b096e14c", # rolled manually
   "material_color_utilities_rev": "799b6ba2f3f1c28c67cc7e0b4f18e0c7d7f3c03e",