Travis CI: Remove MaxPermSize=512M
Travis CI: Remove MaxPermSize=512M

since we are using only Java8 now, where this option no longer exists.

annovanvliet/Smack,vanitasvitae/Smack,Flowdalic/Smack,igniterealtime/Smack,igniterealtime/Smack,esl/Smack,annovanvliet/Smack,Flowdalic/Smack,igniterealtime/Smack,Flowdalic/Smack,vanitasvitae/smack-omemo,vanitasvitae/Smack,esl/Smack,annovanvliet/Smack,esl/Smack,vanitasvitae/Smack,vanitasvitae/smack-omemo,vanitasvitae/smack-omemo