#1424 Broke the generated cmake config files

#1424 replaced the OPENJPEG_INSTALL_INCLUDE_DIR variable, but not replaces all usages. The non existing variable is still used in the code like here:

openjpeg/src/lib/openjp2/CMakeLists.txt

Line 108 in 2d60670

    
           target_include_directories(${OPENJPEG_LIBRARY_NAME} PUBLIC $<INSTALL_INTERFACE:${OPENJPEG_INSTALL_INCLUDE_DIR}>)