Fixed dbfwfilter build failure on Ubuntu

The bison executable didn't generate the headers even though it was instructed
to generate them. This was caused by an older CMake version.

server/modules/filter/dbfwfilter/CMakeLists.txt

@@ -1,7 +1,7 @@
 find_package(FLEX)
 find_package(BISON)
 if(BISON_FOUND AND FLEX_FOUND)
-  bison_target(ruleparser ruleparser.y ${CMAKE_CURRENT_BINARY_DIR}/ruleparser.c DEFINES_FILE ${CMAKE_CURRENT_BINARY_DIR}/ruleparser.yy.h)
+  bison_target(ruleparser ruleparser.y ${CMAKE_CURRENT_BINARY_DIR}/ruleparser.c COMPILE_FLAGS "--defines=${CMAKE_CURRENT_BINARY_DIR}/ruleparser.yy.h")
   flex_target(token token.l ${CMAKE_CURRENT_BINARY_DIR}/token.c COMPILE_FLAGS "--header-file=${CMAKE_CURRENT_BINARY_DIR}/lex.yy.h")
   add_flex_bison_dependency(token ruleparser)
   include_directories(${CMAKE_CURRENT_BINARY_DIR})

server/modules/filter/dbfwfilter/ruleparser.y

@@ -27,8 +27,6 @@
 #include <dbfwfilter.h>
 %}
 
-%defines
-
 /** We need a reentrant scanner so no global variables are used */
 %define api.pure full