build: drop thin archives, not really necessary for now

Author: chergert

build/autotools/SetupLibtool.m4

@@ -1,12 +1,3 @@
-if test -z "$AR_FLAGS"; then
-    if "${AR:-ar}" -V | grep -q 'GNU ar'; then
-        AR_FLAGS="cruT"
-    else
-        AR_FLAGS="cru"
-    fi
-fi
-AC_SUBST([AR_FLAGS])
-
 LT_PREREQ([2.2])
 
 AC_DISABLE_STATIC