Fix include path for bitcoin-config.h in crypto/common.h

All the other files in the repo which include bitcoin-config.h do so with the appropriate subfolder prefixed: config/bitcoin-config.h
The header should be included with the appropriate subfolder here as well.

This canonicalization also allows getting rid of a bit of extra configuration in Makefile.am.

src/Makefile.am

@@ -18,7 +18,6 @@ else
 LIBUNIVALUE = $(UNIVALUE_LIBS)
 endif
 
-BITCOIN_CONFIG_INCLUDES=-I$(builddir)/config
 BITCOIN_INCLUDES=-I$(builddir) -I$(builddir)/obj $(BDB_CPPFLAGS) $(BOOST_CPPFLAGS) $(LEVELDB_CPPFLAGS) $(CRYPTO_CFLAGS) $(SSL_CFLAGS)
 
 BITCOIN_INCLUDES += -I$(srcdir)/secp256k1/include
@@ -250,7 +249,7 @@ libbitcoin_wallet_a_SOURCES = \
   $(BITCOIN_CORE_H)
 
 # crypto primitives library
-crypto_libbitcoin_crypto_a_CPPFLAGS = $(AM_CPPFLAGS) $(BITCOIN_CONFIG_INCLUDES)
+crypto_libbitcoin_crypto_a_CPPFLAGS = $(AM_CPPFLAGS)
 crypto_libbitcoin_crypto_a_CXXFLAGS = $(AM_CXXFLAGS) $(PIE_FLAGS)
 crypto_libbitcoin_crypto_a_SOURCES = \
   crypto/aes.cpp \

src/crypto/common.h

@@ -6,7 +6,7 @@
 #define BITCOIN_CRYPTO_COMMON_H
 
 #if defined(HAVE_CONFIG_H)
-#include "bitcoin-config.h"
+#include "config/bitcoin-config.h"
 #endif
 
 #include <stdint.h>