Do not hardcode -lstdc++

Index: src/tools/aqbanking-cli/Makefile.in
--- src/tools/aqbanking-cli/Makefile.in.orig
+++ src/tools/aqbanking-cli/Makefile.in
@@ -490,7 +490,7 @@ AM_CPPFLAGS = -I$(top_srcdir)/src/libs -I$(top_builddi
 AM_CFLAGS = @visibility_cflags@
 aqbanking_cli_LDADD = \
   $(aqbanking_internal_libs) \
-  $(gwenhywfar_libs) -lstdc++
+  $(gwenhywfar_libs)
 
 aqbanking_cli_SOURCES = \
   main.c \
