Hard coded block limit for pool statistics
Hard coded block limit for pool statistics

This should fix a potential DoS like attack when fetching a random
amount of blocks continously.

Fixes #387

shreeneve/test,studio666/php-mpos,MPOS/php-mpos,mmitech/php-mpos,BlueDragon747/php-mpos,CoinHashMe/MPOS-SSO,machinecoin-project/php-mpos,xisi/php-mpos,sixxkilur/php-mpos,sasselin/xcoin-mpos,shreeneve/test,shreeneve/test,BlueDragon747/php-mpos,bankonme/php-mpos,sasselin/xcoin-mpos,mmitech/php-mpos,studio666/php-mpos,mculp/chunky-mpos,MPOS/php-mpos,xisi/php-mpos,CoinHashMe/MPOS-SSO,bankonme/php-mpos,ychaim/php-mpos,mmitech/php-mpos,sixxkilur/php-mpos,CoinHashMe/MPOS-SSO,CoinHashMe/MPOS-SSO,nimblecoin/web,UNOMP/chunky-mpos,UNOMP/chunky-mpos,nimblecoin/web,nimblecoin/web,evgenyponomarev/pool,evgenyponomarev/pool,mculp/chunky-mpos,studio666/php-mpos,machinecoin-project/php-mpos,bankonme/php-mpos,mculp/chunky-mpos,BlueDragon747/php-mpos,MPOS/php-mpos,UNOMP/chunky-mpos,CoinHashMe/MPOS-SSO,evgenyponomarev/pool,xisi/php-mpos,ychaim/php-mpos,mculp/chunky-mpos,UNOMP/chunky-mpos,sixxkilur/php-mpos,machinecoin-project/php-mpos,ychaim/php-mpos,sasselin/xcoin-mpos