Convert Forms PRO 5.1.5

[mboy]

Here is the upcoming Convert Forms 5.1.6-RC3 , changelog:
Fixed

• Fixed forms list search could re-trigger form export task, causing SQL error when no valid export selection was submitted.
• Fixed AcyMailing 10 deprecation warning about deprecated files being loaded.
• Fixed PHP error (mb_strpos(): Argument #1 must be of type string, array given).
• Fixed calculations returning incorrect results when source fields used input masks.