Add missing space in expected error message.
Add missing space in expected error message.

The space was added in the compiler in #2077, but the corresponding test
was not updated.
Perelandric/ponyc,dipinhora/ponyc,kulibali/ponyc,sgebbie/ponyc,boemmels/ponyc,Theodus/ponyc,ponylang/ponyc,Perelandric/ponyc,Theodus/ponyc,cquinn/ponyc,boemmels/ponyc,kulibali/ponyc,sgebbie/ponyc,boemmels/ponyc,CausalityLtd/ponyc,Theodus/ponyc,boemmels/ponyc,sgebbie/ponyc,dipinhora/ponyc,Perelandric/ponyc,Praetonus/ponyc,Praetonus/ponyc,cquinn/ponyc,CausalityLtd/ponyc,Theodus/ponyc,Praetonus/ponyc,jemc/ponyc,Perelandric/ponyc,cquinn/ponyc,Perelandric/ponyc,ponylang/ponyc,CausalityLtd/ponyc,jemc/ponyc,sgebbie/ponyc,Praetonus/ponyc,kulibali/ponyc,dipinhora/ponyc,boemmels/ponyc,Theodus/ponyc,jemc/ponyc,sgebbie/ponyc,ponylang/ponyc,cquinn/ponyc,kulibali/ponyc