This one is super simple, actually.
Step one, go to your iOS settings app, the one with the gear symbol.
Step two, scroll down and click on the 'General' folder.
Step three, scroll down until you see the 'Keyboard' folder. Click on that. You will see a lot of options.
Step four, turn 'Smart Punctuation' to 'OFF'. The reason this affects your MUDrammer client is because Smart Punctuation uses special quotation marks which are not in the character set supported by the client. Disabling Smart Punctuation will revert your quotation marks to the regular ones, and thus also make apostrophes behave normally again.