Don't allow modifying qvms or pk3s

Exception for allowing pk3s to be downloaded.

code/client/cl_curl.c

@@ -304,7 +304,7 @@ void CL_cURL_PerformDownload(void)
 	}
 	FS_FCloseFile(clc.download);
 	if(msg->msg == CURLMSG_DONE && msg->data.result == CURLE_OK) {
-		FS_SV_Rename(clc.downloadTempName, clc.downloadName);
+		FS_SV_Rename(clc.downloadTempName, clc.downloadName, qfalse);
 		clc.downloadRestart = qtrue;
 	}
 	else {

code/client/cl_parse.c

@@ -637,7 +637,7 @@ void CL_ParseDownload ( msg_t *msg ) {
 			clc.download = 0;
 
 			// rename the file
-			FS_SV_Rename ( clc.downloadTempName, clc.downloadName );
+			FS_SV_Rename ( clc.downloadTempName, clc.downloadName, qfalse );
 		}
 
 		// send intentions now