linstor-common: use input file modification date for copyright range

rp- · rp- · commit e4988aeaabbd · 2020-08-03T11:51:02.000+02:00
diff --git a/linstor-common b/linstor-common
@@ -1 +1 @@
-Subproject commit 1070d090352232ac4b3ff66cd9dcc7924a64ecd5
+Subproject commit 6ff3445b50fb3f6b0b5b107c9fe6665464e42be1
