CONFDB: Fixed some missing dependencies in a header file

confdb_setup.h did not include all the header files it requires.
So far those files happened to be included before this file, so
no compilation error occurred, but the problem was hiding in the
shadows.

src/confdb/confdb_setup.h

@@ -22,6 +22,10 @@
 #ifndef CONFDB_SETUP_H_
 #define CONFDB_SETUP_H_
 
+#include <talloc.h>
+
+#include "util/util_errors.h"
+
 #define CONFDB_BASE_LDIF \
      "dn: @ATTRIBUTES\n" \
      "cn: CASE_INSENSITIVE\n" \
@@ -37,6 +41,8 @@
      "@LIST: server_sort\n" \
      "\n"
 
+struct confdb_ctx;
+
 errno_t confdb_setup(TALLOC_CTX *mem_ctx,
                      const char *cdb_file,
                      const char *config_file,