x11/kdelibs4: unbreak consumers with hunspell 1.5

$ make -C devel/lokalize
[...]

• Could NOT find HUNSPELL (missing: HUNSPELL_LIBRARIES)

CMake Error at /usr/local/share/cmake/Modules/FindPackageHandleStandardArgs.cmake:148 (message):

Could NOT find HUNSPELL (missing: HUNSPELL_LIBRARIES)

Call Stack (most recent call first):

/usr/local/share/cmake/Modules/FindPackageHandleStandardArgs.cmake:388 (_FPHSA_FAILURE_MESSAGE)
/usr/local/share/apps/cmake/modules/FindHUNSPELL.cmake:22 (FIND_PACKAGE_HANDLE_STANDARD_ARGS)
src/CMakeLists.txt:4 (find_package)

PR: 214837
Approved by: portmgr blanket