Add -lstdc++ -lsupc++ in configure.ac not in android-config

Also make sure that those flags do not appear in libwslay LIBS.

android-config

@@ -52,7 +52,6 @@ PATH=$TOOLCHAIN/bin:$PATH
     --with-libz --with-libz-prefix=$PREFIX \
     CXXFLAGS="-Os -g" \
     CFLAGS="-Os -g" \
-    LIBS="-lstdc++ -lsupc++" \
     LDFLAGS="-L$PREFIX/lib" \
     PKG_CONFIG_LIBDIR="$PREFIX/lib/pkgconfig" \
     ZLIB_LIBS="-lz" \

configure.ac

@@ -612,6 +612,14 @@ AM_CONDITIONAL([ENABLE_WEBSOCKET], [test "x$enable_websocket" = "xyes"])
 
 AC_SUBST([bashcompletiondir])
 
+case "$host" in
+  *android*)
+    LIBS="$LIBS -lstdc++ -lsupc++"
+    ;;
+  *)
+    ;;
+esac
+
 if test "x$ARIA2_STATIC" = "xyes"; then
   LDFLAGS="$LDFLAGS -all-static -static-libgcc -static-libstdc++"
   dnl For non-MinGW build, we need additional libs for static build.