Removed not needed Index on sessions table.
Removed not needed Index on sessions table.

oiami/otrs,moritz/otrs,muehlbauer/otrs,s7design/otrs,oiami/otrs,brandonshults01/otrs,noritnk/otrs,StCyr/otrs,rudy500/otrs,PortgasDAce/otrs,moritz/otrs,linearregression/otrs,noritnk/otrs,xhoy/otrs,linearregression/otrs,oiami/otrs,muehlbauer/otrs,mburggraf/otrs,vlascoder/otrs,oiami/otrs,rudy500/otrs,rudy500/otrs,s7design/otrs,thorsteneckel/otrs,crythias/otrs,nilei/otrs,linearregression/otrs,PortgasDAce/otrs,StCyr/otrs,vlascoder/otrs,eliasp/otrs,MBRG/otrs,vlascoder/otrs,PortgasDAce/otrs,mburggraf/otrs,xhoy/otrs,MBRG/otrs,mburggraf/otrs,thorsteneckel/otrs,capeit-tto/otrs,crythias/otrs,xhoy/otrs,crythias/otrs,muehlbauer/otrs,brandonshults01/otrs,brandonshults01/otrs,PortgasDAce/otrs,thorsteneckel/otrs,muehlbauer/otrs,nilei/otrs,xhoy/otrs,rudy500/otrs,mbeijen/otrs-1,s7design/otrs,capeit-tto/otrs,eliasp/otrs,thorsteneckel/otrs,nilei/otrs,s7design/otrs,mburggraf/otrs,mbeijen/otrs-1,eliasp/otrs,balazj/otrs,StCyr/otrs,moritz/otrs,brandonshults01/otrs,linearregression/otrs,moritz/otrs,linearregression/otrs,oiami/otrs,balazj/otrs,MBRG/otrs,s7design/otrs,capeit-tto/otrs,nilei/otrs,noritnk/otrs,PortgasDAce/otrs,muehlbauer/otrs,nilei/otrs,crythias/otrs,balazj/otrs,eliasp/otrs,mburggraf/otrs,MBRG/otrs,balazj/otrs,rudy500/otrs,StCyr/otrs,moritz/otrs,xhoy/otrs,MBRG/otrs,eliasp/otrs,brandonshults01/otrs,mbeijen/otrs-1,StCyr/otrs,crythias/otrs,thorsteneckel/otrs,balazj/otrs