Refer to actual block size in sigops limit

For compatibility with peers that may not be observing BIP100,
the scaled sigops limit will refer to actual block size rather
than hardLimit.

bip-0100.mediawiki

@@ -47,7 +47,7 @@ The system is compatible with emergent consensus, but whereas under that system
 ### Otherwise, <code>new hardLimit</code> remains the same as <code>current hardLimit</code>.
 
 ===Signature Hashing Operations Limits===
-# The per-block signature hashing operations limit is scaled to (<code>hardLimit</code> rounded up to nearest megabyte)/50.
+# The per-block signature hashing operations limit is scaled to (actual block size rounded up to nearest megabyte)/50.
 # A maximum serialized transaction size of 1000000 bytes is imposed.
 
 ===Publication of <code>hardLimit</code>===