Do not hardcode -lstdc++

Index: src/tools/aqbanking-cli/Makefile.in
--- src/tools/aqbanking-cli/Makefile.in.orig
+++ src/tools/aqbanking-cli/Makefile.in
@@ -496,8 +496,7 @@ aqcli_libs = ${abs_top_builddir}/src/libs/cli/libaqcli
 aqbanking_cli_LDADD = \
   $(aqbanking_internal_libs) \
   $(gwenhywfar_libs) \
-  $(aqcli_libs) \
-  -lstdc++
+  $(aqcli_libs)
 
 aqbanking_cli_SOURCES = \
   main.c \
