HPCC-26479 Improve the git authentication for remote eclccserver

Fix build error on MacOS

Signed-off-by: Richard Chapman <rchapman@hpccsystems.com>

system/jlib/jutil.cpp

@@ -48,6 +48,7 @@
 #include <signal.h>
 #include <paths.h>
 #include <cmath>
+#include <string>
 #endif
 
 #include <limits.h>