Also add a no-op stub for OPENSSL_config.

Apparently OpenSSL's API is made entirely of initialization functions.
Some external libraries like to initialize with OPENSSL_config instead.

Change-Id: I28efe97fc5eb21309f560c84112b80e947f8bb17
Reviewed-on: https://boringssl-review.googlesource.com/6981
Reviewed-by: Adam Langley <agl@google.com>

crypto/conf/conf.c

@@ -783,3 +783,5 @@ int CONF_modules_load_file(CONF_MUST_BE_NULL *filename, const char *appname,
 }
 
 void CONF_modules_free(void) {}
+
+void OPENSSL_config(CONF_MUST_BE_NULL *config_name) {}

include/openssl/conf.h

@@ -152,6 +152,9 @@ OPENSSL_EXPORT int CONF_modules_load_file(CONF_MUST_BE_NULL *filename,
 /* CONF_modules_free does nothing. */
 OPENSSL_EXPORT void CONF_modules_free(void);
 
+/* OPENSSL_config does nothing. */
+OPENSSL_EXPORT void OPENSSL_config(CONF_MUST_BE_NULL *config_name);
+
 
 #if defined(__cplusplus)
 }  /* extern C */