make: avo_alloca.h works around a very old Solaris bug, delete it

*** 30,40 ****
   */
  
  /*
   * Included files
   */
! #include <avo/avo_alloca.h>             /* alloca() */
  #if defined(TEAMWARE_MAKE_CMN)
  #include <avo/util.h>           /* avo_get_user(), avo_hostname() */
  #endif
  
  #if defined(DISTRIBUTED) || defined(MAKETOOL) /* tolik */
--- 30,40 ----
   */
  
  /*
   * Included files
   */
! #include <alloca.h>             /* alloca() */
  #if defined(TEAMWARE_MAKE_CMN)
  #include <avo/util.h>           /* avo_get_user(), avo_hostname() */
  #endif
  
  #if defined(DISTRIBUTED) || defined(MAKETOOL) /* tolik */