Disable all DLL init functions in libgpg-error, since they're
not actually run in statically linked libs. And libtool seems
to unconditionally set that flag on all Windows builds.

diff -ur libgpg-error.org/src/init.c libgpg-error/src/init.c
--- libgpg-error.org/src/init.c	2017-02-28 10:11:05.000000000 +0100
+++ libgpg-error/src/init.c	2017-11-23 16:44:56.850797400 +0100
@@ -88,7 +88,7 @@
 _gpg_err_init (void)
 {
 #ifdef HAVE_W32_SYSTEM
-# ifdef DLL_EXPORT
+# ifdef HAVE_DLL_INIT
   /* We always have a constructor and thus this function is called
      automatically.  Due to the way the C init code of mingw works,
      the constructors are called before our DllMain function is
@@ -130,7 +130,7 @@
 void
 _gpg_err_deinit (int mode)
 {
-#if defined (HAVE_W32_SYSTEM) && !defined(DLL_EXPORT)
+#if defined (HAVE_W32_SYSTEM) && !defined(HAVE_DLL_INIT)
   struct tls_space_s *tls;
 
   tls = TlsGetValue (tls_index);
@@ -473,7 +473,7 @@
 
 
 /* Entry point called by the DLL loader.  */
-#ifdef DLL_EXPORT
+#ifdef HAVE_DLL_INIT
 int WINAPI
 DllMain (HINSTANCE hinst, DWORD reason, LPVOID reserved)
 {
diff -ur libgpg-error.org/src/w32-gettext.c libgpg-error/src/w32-gettext.c
--- libgpg-error.org/src/w32-gettext.c	2016-12-02 22:51:19.000000000 +0100
+++ libgpg-error/src/w32-gettext.c	2017-11-23 16:43:28.450453000 +0100
@@ -1180,7 +1180,7 @@
    DLL.  If used as a static lib we can't control the process set; for
    example it might be used with a main module which is not build with
    mingw and thus does not know how to call the constructors.  */
-#ifdef DLL_EXPORT
+#ifdef HAVE_DLL_INIT
 static void module_init (void) _GPG_ERR_CONSTRUCTOR;
 #endif
 static void
@@ -1195,7 +1195,7 @@
     }
 }
 
-#if !defined(DLL_EXPORT) || !defined(_GPG_ERR_HAVE_CONSTRUCTOR)
+#if !defined(HAVE_DLL_INIT) || !defined(_GPG_ERR_HAVE_CONSTRUCTOR)
 void
 _gpg_w32__init_gettext_module (void)
 {