Reduce the number of warnings about missing initializers.

diff --git a/server/registry.c b/server/registry.c
index 3ca1c37..3375e50 100644
--- a/server/registry.c
+++ b/server/registry.c
@@ -1052,7 +1052,7 @@
         { "hex:",      4,   REG_BINARY,          REG_BINARY },
         { "dword:",    6,   REG_DWORD,           REG_DWORD },
         { "hex(",      4,   -1,                  REG_BINARY },
-        { NULL, }
+        { NULL,        0,    0,                  0 }
     };
 
     const struct data_type *ptr;