Fix "strlen(): Passing null to parameter #1 of type string is deprecated"
Fix "strlen(): Passing null to parameter #1 of type string is deprecated"

haeflimi/concrete5,mlocati/concrete5,biplobice/concrete5,mlocati/concrete5,jaromirdalecky/concrete5,biplobice/concrete5,jaromirdalecky/concrete5,biplobice/concrete5,biplobice/concrete5,concrete5/concrete5,mlocati/concrete5,mlocati/concrete5,concrete5/concrete5,jaromirdalecky/concrete5,concrete5/concrete5,deek87/concrete5,haeflimi/concrete5,concrete5/concrete5,haeflimi/concrete5,haeflimi/concrete5,deek87/concrete5,jaromirdalecky/concrete5,deek87/concrete5,deek87/concrete5