syncthing: remove unneeded patch

packages/syncthing/no_ioprioSet.patch

@@ -1,19 +0,0 @@
-diff -uNr syncthing/lib/osutil/lowprio_linux.go syncthing.mod/lib/osutil/lowprio_linux.go
---- syncthing/lib/osutil/lowprio_linux.go	2018-03-06 08:19:07.000000000 +0200
-+++ syncthing.mod/lib/osutil/lowprio_linux.go	2018-05-02 13:03:12.463566932 +0300
-@@ -30,13 +30,8 @@
- )
- 
- func ioprioSet(class ioprioClass, value int) error {
--	res, _, err := syscall.Syscall(syscall.SYS_IOPRIO_SET,
--		uintptr(ioprioWhoProcess), 0,
--		uintptr(class)<<ioprioClassShift|uintptr(value))
--	if res == 0 {
--		return nil
--	}
--	return err
-+    // Android 8 does not allow syscall SYS_IOPRIO_SET
-+    return nil
- }
- 
- // SetLowPriority lowers the process CPU scheduling priority, and possibly