Merge bitcoin-core/secp256k1#1200: Drop no longer used Autoheader macros

9b7d186 Drop no longer used Autoheader macros (Hennadii Stepanov)

Pull request description:

  A cleanup after bitcoin#1178.

ACKs for top commit:
  kevkevinpal:
    utACK [9b7d186](bitcoin-core/secp256k1@9b7d186)
  sipa:
    utACK 9b7d186
  real-or-random:
    utACK 9b7d186

Tree-SHA512: ce95547683580bde46a55a6adc3dc46aca02fc86b0300ce0598d62ed47f1d77c4fa9ffd38dcda858655cefa6c940260d05f42cca294e7f3e7a46394b117c9ce9

configure.ac

@@ -22,9 +22,6 @@ AC_INIT([libsecp256k1],m4_join([.], _PKG_VERSION_MAJOR, _PKG_VERSION_MINOR, _PKG
 AC_CONFIG_AUX_DIR([build-aux])
 AC_CONFIG_MACRO_DIR([build-aux/m4])
 AC_CANONICAL_HOST
-AH_TOP([#ifndef LIBSECP256K1_CONFIG_H])
-AH_TOP([#define LIBSECP256K1_CONFIG_H])
-AH_BOTTOM([#endif /*LIBSECP256K1_CONFIG_H*/])
 
 # Require Automake 1.11.2 for AM_PROG_AR
 AM_INIT_AUTOMAKE([1.11.2 foreign subdir-objects])