Fixed HTTP parsing when in insecure mode.
Fixed HTTP parsing when in insecure mode.

Parsing would ignore the size of data already buffered, resulting in bad_alloc exception.
Fixes #2898.

johnsoch/cuberite,Altenius/cuberite,nounoursheureux/MCServer,mc-server/MCServer,Schwertspize/cuberite,tonibm19/cuberite,marvinkopf/cuberite,mc-server/MCServer,marvinkopf/cuberite,nounoursheureux/MCServer,Frownigami1/cuberite,johnsoch/cuberite,marvinkopf/cuberite,Schwertspize/cuberite,Altenius/cuberite,johnsoch/cuberite,nounoursheureux/MCServer,QUSpilPrgm/cuberite,tonibm19/cuberite,Frownigami1/cuberite,Frownigami1/cuberite,nounoursheureux/MCServer,QUSpilPrgm/cuberite,mc-server/MCServer,tonibm19/cuberite,kevinr/cuberite,Schwertspize/cuberite,kevinr/cuberite,marvinkopf/cuberite,kevinr/cuberite,tonibm19/cuberite,QUSpilPrgm/cuberite,marvinkopf/cuberite,QUSpilPrgm/cuberite,Altenius/cuberite,Schwertspize/cuberite,johnsoch/cuberite,nounoursheureux/MCServer,mc-server/MCServer,marvinkopf/cuberite,mc-server/MCServer,Frownigami1/cuberite,QUSpilPrgm/cuberite,Altenius/cuberite,tonibm19/cuberite,Frownigami1/cuberite,mc-server/MCServer,johnsoch/cuberite,nounoursheureux/MCServer,Altenius/cuberite,tonibm19/cuberite,kevinr/cuberite,Schwertspize/cuberite,kevinr/cuberite,QUSpilPrgm/cuberite,kevinr/cuberite