debian: mod_java depends on gcj-jdk for a symlink to jni.h

See:
 http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=371060

debian/control-modules

@@ -500,7 +500,7 @@ Distro-Conflicts: squeeze
 Module: languages/mod_java
 Description: mod_java
  Adds mod_java.
-Build-Depends: default-jdk
+Build-Depends: default-jdk, gcj-jdk
 
 Module: languages/mod_lua
 Description: mod_lua