Help: Fix regex in example of cmake-packages(7)

This change makes it work as intended as opposed to make the condition always true.
This can be confirmed by running the following script:
```
[johel@sundown tmp]$ cat x.cmake 
function(f)
  set(valid_inputs abc 123)
  foreach(input ${ARGV})
    if(";${valid_inputs};" MATCHES input)
      message("old valid: ${input}")
    endif()
    if(";${valid_inputs};" MATCHES ";${input};")
      message("new valid: ${input}")
    endif()
  endforeach()
endfunction()

f("0;z;123;12;abc;ab;13;ac")

set(_supported_components Plot Table)
set(ClimbingStats_FIND_COMPONENTS Plot Table P T)

foreach(_comp ${ClimbingStats_FIND_COMPONENTS})
  if(NOT ";${_supported_components};" MATCHES _comp)
    message("old invalid: set(ClimbingStats_NOT_FOUND_MESSAGE \"Unsupported component: ${_comp}\")")
  endif()
  if(NOT ";${_supported_components};" MATCHES ";${_comp};")
    message("new invalid: set(ClimbingStats_NOT_FOUND_MESSAGE \"Unsupported component: ${_comp}\")")
  endif()
endforeach()
[johel@sundown tmp]$ cmake -P x.cmake 
new valid: 123
new valid: abc
old invalid: set(ClimbingStats_NOT_FOUND_MESSAGE "Unsupported component: Plot")
old invalid: set(ClimbingStats_NOT_FOUND_MESSAGE "Unsupported component: Table")
old invalid: set(ClimbingStats_NOT_FOUND_MESSAGE "Unsupported component: P")
new invalid: set(ClimbingStats_NOT_FOUND_MESSAGE "Unsupported component: P")
old invalid: set(ClimbingStats_NOT_FOUND_MESSAGE "Unsupported component: T")
new invalid: set(ClimbingStats_NOT_FOUND_MESSAGE "Unsupported component: T")
```

0 files changed, 0 insertions, 0 deletions