configure: bitcoin-tx doesn't need libevent, so don't pull it in

configure.ac

@@ -1101,7 +1101,7 @@ if test x$use_pkgconfig = xyes; then
       if test x$use_qr != xno; then
         BITCOIN_QT_CHECK([PKG_CHECK_MODULES([QR], [libqrencode], [have_qrencode=yes], [have_qrencode=no])])
       fi
-      if test x$build_bitcoin_cli$build_bitcoin_tx$build_bitcoind$bitcoin_enable_qt$use_tests != xnonononono; then
+      if test x$build_bitcoin_cli$build_bitcoind$bitcoin_enable_qt$use_tests != xnononono; then
         PKG_CHECK_MODULES([EVENT], [libevent],, [AC_MSG_ERROR(libevent not found.)])
         if test x$TARGET_OS != xwindows; then
           PKG_CHECK_MODULES([EVENT_PTHREADS], [libevent_pthreads],, [AC_MSG_ERROR(libevent_pthreads not found.)])
@@ -1126,7 +1126,7 @@ else
   AC_CHECK_HEADER([openssl/ssl.h],, AC_MSG_ERROR(libssl headers missing),)
   AC_CHECK_LIB([ssl],         [main],SSL_LIBS=-lssl, AC_MSG_ERROR(libssl missing))
 
-  if test x$build_bitcoin_cli$build_bitcoin_tx$build_bitcoind$bitcoin_enable_qt$use_tests != xnonononono; then
+  if test x$build_bitcoin_cli$build_bitcoind$bitcoin_enable_qt$use_tests != xnononono; then
     AC_CHECK_HEADER([event2/event.h],, AC_MSG_ERROR(libevent headers missing),)
     AC_CHECK_LIB([event],[main],EVENT_LIBS=-levent,AC_MSG_ERROR(libevent missing))
     if test x$TARGET_OS != xwindows; then