Fix braces in if-else statements

From the Linux kernel coding guidelines:

    Do not unnecessarily use braces where a single statement will do.
    [...] This does not apply if one branch of a conditional statement
    is a single statement. Use braces in both branches.

Signed-off-by: Lukas Fleischer <calcurse@cryptocrack.de>

src/sha1.c

@@ -197,8 +197,9 @@ void sha1_update(sha1_ctx_t * ctx, const uint8_t * data, unsigned int len)
     for (; i + 63 < len; i += 64)
       sha1_transform(ctx->state, &data[i]);
     j = 0;
-  } else
+  } else {
     i = 0;
+  }
   memcpy(&ctx->buffer[j], &data[i], len - i);
 }