Separate out error messages if firebird include dir or lib dir cannot be found.

CMakeLists.txt

@@ -115,6 +115,10 @@ find_path(FIREBIRD_INCLUDE_DIR ibase.h
     $ENV{ProgramFiles}/Firebird/*/include
 )
 
+if(NOT FIREBIRD_INCLUDE_DIR )
+    message(FATAL_ERROR "MyFirstUDRKit build: Location of Firebird include files could not be found")
+endif()
+
 set(FIREBIRD_LIB_NAMES fbclient fbclient_ms)
 find_library(FIREBIRD_LIB_DIR
     NAMES
@@ -126,7 +130,7 @@ find_library(FIREBIRD_LIB_DIR
         $ENV{ProgramFiles}/Firebird/*/lib
 )
 
-if(NOT FIREBIRD_INCLUDE_DIR OR NOT FIREBIRD_LIB_DIR)
+if( NOT FIREBIRD_LIB_DIR)
     message(FATAL_ERROR "MyFirstUDRKit build: Location of Firebird library could not be found")
 endif()