(trivial) blockref: rephrase stripping leading zeroes from hash

Author: SomberNight

docs/protocol-basics.rst

@@ -234,10 +234,9 @@ However, it helps the client to also provide the corresponding height,
 otherwise the client might need to maintain some kind of blockhash->blockheight map,
 which (naively) for a million blocks might take ~50-100 MB of RAM (or disk space).
 
-To save some bandwidth, we can strip the leading zeroes (from the hex representation!)
-of the block hash. We only strip the zero hex characters from the low-entropy end,
-and as the length of the full blockhash is a known constant, this leaves the compressed
-representation unambiguous.
+To save some bandwidth, we strip the leading zeroes (which result from mining difficulty)
+from the hex representation of the block hash. As the length of the full blockhash
+is a known constant, this leaves the compressed representation unambiguous.
 
 The `blockref` is a `(block_height, compressed_blockhash)` pair, serialized as a json array.
 `block_height` is an integer, the corresponding height for `compressed_blockhash`.