[CMake] CTEST_ENVIRONMENT in "non-declarative" script

[Milan Dorak]

Hey guyz, i have been using "declarative" ctest script and command
SET (CTEST_ENVIRONMENT
"LC_ALL=C"
)

This isn't working in new "non-declarative" scripts.
Sure I can do "export LC_ALL=C", but i would rather have it in script 
like before.

Any suggestions ? Thanks