Remove USE_STRING2 hack. No longer needed since nsString2 is the default.

config/autoconf.mk.in

@@ -51,8 +51,6 @@ BUILD_IDLC = @BUILD_IDLC@
 MODULAR_NETLIB  = @MODULAR_NETLIB@
 STANDALONE_IMAGE_LIB = @STANDALONE_IMAGE_LIB@
 
-USE_STRING2 = @USE_STRING2@
-
 MOZ_ENABLE_GTK_MOZILLA     = @MOZ_ENABLE_GTK_MOZILLA@
 MOZ_BUILD_ROOT             = @MOZ_BUILD_ROOT@
 

configure.in

@@ -1537,24 +1537,6 @@ MOZ_ARG_WITH_STRING(wrap-malloc,
 [  --with-wrap-malloc-=\$dir Location of malloc wrapper library],
   WRAP_MALLOC_LIB=$withval)
 
-
-dnl ========================================================
-dnl =
-dnl = nsString hackery - This is expected to be a short-lived
-dnl = variable.  It will be yanked once nsString2 replaces
-dnl = nsString completely.
-dnl = 
-dnl ========================================================
-MOZ_ARG_ENABLE_BOOL(string2,
-[  --enable-string2           Enable the use of nsString2 ],
-  USE_STRING2=1)
-
-if test "$USE_STRING2"
-then
-  AC_DEFINE(USE_STRING2)
-fi
-
-
 dnl ========================================================
 dnl =
 dnl = Misc. Options