changed #!/bin/sh to #!/bin/dash in order to increase the performance of cgi and fcgi wrappers

dash is much more faster than bash, which usually is the default shell of ispconfig servers.

this changes have been tested and should increase the performance of php being run using cgi and fcgi wrappers.

reference: http://unix.stackexchange.com/questions/148035/is-dash-or-some-other-shell-faster-than-bash