Fix typo in documentation (CTR warning)
diff --git a/include/mbedtls/blowfish.h b/include/mbedtls/blowfish.h
index 4b4916e..f4e8afc 100644
--- a/include/mbedtls/blowfish.h
+++ b/include/mbedtls/blowfish.h
@@ -184,7 +184,7 @@
  *             2. Use a randomly-generated \p nonce_counter for each call.
  *             With this strategy, you need to ensure the nonce is generated
  *             in an unbiased way and you must not encrypt more than 2**32
- *             block of data.
+ *             blocks of data.
  *
  *             Note that for both stategies, the limit is in number of blocks
  *             and that a Blowfish block is 8 bytes.