Bumping cpprestsdk for build fix (#247)

AesteroidBlues · jasonsandlin · commit 279d760731f7 · 2017-08-10T14:42:32.000-07:00
diff --git a/External/cpprestsdk b/External/cpprestsdk
@@ -1 +1 @@
-Subproject commit 9c86decdef094e3eb0dca7f79155f977e6b5094e
+Subproject commit b98e9f173cfd818e0225b0698689b806b2aad054
