fix cmake warning

Author: jef-n

cmake/FindProj.cmake

@@ -57,9 +57,9 @@ IF (PROJ_FOUND)
      STRING(REGEX REPLACE "^.*PROJ_VERSION_MINOR +([0-9]+).*$" "\\1" PROJ_VERSION_MINOR "${proj_version}")
      STRING(REGEX REPLACE "^.*PROJ_VERSION_PATCH +([0-9]+).*$" "\\1" PROJ_VERSION_PATCH "${proj_version}")
      STRING(CONCAT PROJ_VERSION_STR "(" ${PROJ_VERSION_MAJOR} "." ${PROJ_VERSION_MINOR} "." ${PROJ_VERSION_PATCH} ")")
-   ELSE(EXISTS)
+   ELSE(EXISTS ${PROJ_INCLUDE_DIR}/proj.h)
      SET(PROJ_VERSION_MAJOR 4)
-   ENDIF (EXISTS)
+   ENDIF(EXISTS ${PROJ_INCLUDE_DIR}/proj.h)
    IF (NOT PROJ_FIND_QUIETLY)
      MESSAGE(STATUS "Found Proj: ${PROJ_LIBRARY} version ${PROJ_VERSION_MAJOR} ${PROJ_VERSION_STR}")
    ENDIF (NOT PROJ_FIND_QUIETLY)