Increment version number of object files

The previous change has broken compatibility of object files, so it is
needed to increment the version number to make the linker reject files
generated with the old code.

Signed-off-by: Antonio Niño Díaz <[email protected]>

src/asm/output.c

@@ -504,7 +504,7 @@ out_WriteObject(void)
 		struct PatchSymbol *pSym;
 		struct Section *pSect;
 
-		fwrite("RGB4", 1, 4, f);
+		fwrite("RGB5", 1, 4, f);
 		fputlong(countsymbols(), f);
 		fputlong(countsections(), f);
 

src/link/object.c

@@ -336,8 +336,7 @@ obj_ReadOpenFile(FILE * pObjfile, char *tzObjectfile)
 	tzHeader[4] = 0;
 	if (strncmp(tzHeader, "RGB", 3) == 0) {
 		switch (tzHeader[3]) {
-		case '3':
-		case '4': // V4 supports OAM sections, but is otherwise identical
+		case '5':
 			obj_ReadRGB(pObjfile);
 			break;
 		default: