games/edge: Fix build with Clang 6

deh_edge/english.h:35:63: error: invalid suffix on literal; C++11 requires a space between literal and identifier [-Wreserved-user-defined-literal]
#define LOADNET "you can't do load while in a net game!\n\n"PRESSKEY

^

http://beefy12.nyi.freebsd.org/data/head-amd64-default/p475044_s336572/logs/edge-1.35_9.log