Merge topic 'check-Werror-CMP0066'

cebcc07a80 CheckSymbolExists: Remove -Werror from per-config flags
06c99ce73b CheckSymbolExists: Avoid removing the flag after -Werror
e60281e968 CMakeDetermineCompilerABI: Remove -Werror from per-config flags
6abd25e7fd Help: Fix a typo

Acked-by: Kitware Robot <kwrobot@kitware.com>
Acked-by: buildbot <buildbot@kitware.com>
Merge-request: !9377