build: remove jpeg lib check from bitcoin_qt.m4

build-aux/m4/bitcoin_qt.m4

@@ -468,7 +468,6 @@ AC_DEFUN([_BITCOIN_QT_FIND_LIBS_WITHOUT_PKGCONFIG],[
   ])
 
   BITCOIN_QT_CHECK(AC_CHECK_LIB([z] ,[main],,AC_MSG_WARN([zlib not found. Assuming qt has it built-in])))
-  BITCOIN_QT_CHECK(AC_SEARCH_LIBS([jpeg_create_decompress] ,[qtjpeg jpeg],,AC_MSG_WARN([libjpeg not found. Assuming qt has it built-in])))
   if test x$bitcoin_cv_qt58 = xno; then
     BITCOIN_QT_CHECK(AC_SEARCH_LIBS([png_error] ,[qtpng png],,AC_MSG_WARN([libpng not found. Assuming qt has it built-in])))
     BITCOIN_QT_CHECK(AC_SEARCH_LIBS([pcre16_exec], [qtpcre pcre16],,AC_MSG_WARN([libpcre16 not found. Assuming qt has it built-in])))