Tweaks for gcc 10 compiling, thanks OC

src/main.c

@@ -5,6 +5,8 @@
 	View README file supplied with this software for more details
 */
 
+#define MY_GLOBAL
+
 #include "deps.h"
 #include "util.h"
 #include "functions.h"

src/vars.h

@@ -5,6 +5,10 @@
     View README file supplied with this software for more details
 */
 
+#ifndef   MY_GLOBAL
+#define   MY_GLOBAL extern
+#endif /* MY_GLOBAL */
+
 struct s_variables
 {
     char var_name [MAX_VAR_NAME_LEN];
@@ -12,7 +16,7 @@ struct s_variables
 };
 
 typedef struct s_variables VARS;
-VARS svars[MAXVARS];
+MY_GLOBAL VARS svars [MAXVARS];
 
 void set_var(int index, char *varname, char *vardata);
 int get_var_count();