Update gridtracker.i386.spec to use the previously created tar.gz as source for the rpm

gridtracker.i386.spec

@@ -7,7 +7,8 @@ Name:           gridtracker
 Summary:        GridTracker: An amateur radio companion to WSJT-X or JTDX
 Version:        %{version}
 Release:        1%{?dist}
-BuildArch:	    i386
+BuildArch:	   i386
+Source0:        GridTracker-%{version}-linux-x86.tar.gz
 
 License:        BSD 3-Clause License
 URL:            https://gridtracker.org