Ember: Fix error template
Ember: Fix error template

Although I'm not sure if it's a good idea to show the stack trace and everything
here even in production mode...

Susurrus/crates.io,steveklabnik/crates.io,rust-lang/crates.io,Susurrus/crates.io,Susurrus/crates.io,achanda/crates.io,rust-lang/crates.io,achanda/crates.io,rust-lang/crates.io,rust-lang/crates.io,steveklabnik/crates.io,steveklabnik/crates.io,Susurrus/crates.io,steveklabnik/crates.io,achanda/crates.io,achanda/crates.io