devapp/owners: remove mikioh entries

We have not had successful contact with mikioh since April, 2019.
Remove owner entries so that we're not continuously CCing an account
that has become unresponsive. We can reinstate them in the seemingly
unlikely event of a reappearance.

Move up secondary owners to primary where available.

Change-Id: I1e1ff324601e866ce6d34179bf03dfc4826e6508
Reviewed-on: https://go-review.googlesource.com/c/build/+/264758
Trust: Dmitri Shuralyov <dmitshur@golang.org>
Run-TryBot: Dmitri Shuralyov <dmitshur@golang.org>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
diff --git a/devapp/owners/table.go b/devapp/owners/table.go
index 6317412..ae46261 100644
--- a/devapp/owners/table.go
+++ b/devapp/owners/table.go
@@ -424,8 +424,7 @@
 		Primary: []Owner{bradfitz, minux},
 	},
 	"go/src/net": {
-		Primary:   []Owner{mikioh},
-		Secondary: []Owner{bradfitz, iant},
+		Primary: []Owner{bradfitz, iant},
 	},
 	"go/src/net/http": {
 		Primary:   []Owner{bradfitz},
@@ -435,7 +434,7 @@
 		Primary: []Owner{rsc},
 	},
 	"go/src/net/internal/socktest": {
-		Primary: []Owner{mikioh},
+		Primary: []Owner{},
 	},
 	"go/src/net/mail": {
 		Primary:   []Owner{},
@@ -594,8 +593,7 @@
 	},
 
 	"net": {
-		Primary:   []Owner{mikioh},
-		Secondary: []Owner{bradfitz, iant},
+		Primary: []Owner{bradfitz, iant},
 	},
 	"net/bpf": {
 		Primary: []Owner{danderson, mdlayher},
@@ -609,13 +607,13 @@
 		Secondary: []Owner{empijei},
 	},
 	"net/icmp": {
-		Primary: []Owner{mikioh},
+		Primary: []Owner{},
 	},
 	"net/ipv4": {
-		Primary: []Owner{mikioh, iant},
+		Primary: []Owner{iant},
 	},
 	"net/ipv6": {
-		Primary: []Owner{mikioh, iant},
+		Primary: []Owner{iant},
 	},
 
 	"oauth2": {