Fix the 0.3.4 part of bug 27781 (arm compilation)

Because with arm on OpenSSL <1.1 we don't define USE_EVP_AES_CTR, we
need to include crypto_util.h here.

changes/bug27781

@@ -0,0 +1,4 @@
+  o Major bugfixes (compilation):
+    - Fix compilation on arm (and other less-used CPUs)
+      when compiling with OpenSSL before 1.1. Fixes bug 27781;
+      bugfix on 0.3.4.1-alpha.

src/common/aes.c

@@ -41,6 +41,7 @@ ENABLE_GCC_WARNING(redundant-decls)
 #include "util.h"
 #include "torlog.h"
 #include "di_ops.h"
+#include "crypto_util.h"
 
 #ifdef ANDROID
 /* Android's OpenSSL seems to have removed all of its Engine support. */
@@ -407,4 +408,3 @@ aes_set_iv(aes_cnt_cipher_t *cipher, const uint8_t *iv)
 }
 
 #endif /* defined(USE_EVP_AES_CTR) */
-