nixos-module/container/bird: simplify filter operations

nix/nixos-module/container/bird.nix

@@ -40,14 +40,14 @@ in
           ''}
           ${lib.optionalString isUpstream ''
             export filter {
-              if net ~ [ 0.0.0.0/0 ] then {
+              if net = 0.0.0.0/0 then {
                 # Do not set another default route on upstreams
                 reject;
               }
               accept;
             };
             import filter {
-              if net ~ [ 0.0.0.0/0 ] then {
+              if net = 0.0.0.0/0 then {
                 # Learn the upstream default route
                 accept;
               }
@@ -64,7 +64,7 @@ in
           ''}
           ${lib.optionalString isUpstream ''
             export filter {
-              if net ~ [ ::/0 ] then {
+              if net = ::/0 then {
                 # Do not set another default route on upstreams
                 reject;
               }
@@ -72,7 +72,7 @@ in
             };
             # Learn the upstream default route
             import filter {
-              if net ~ [ ::/0 ] then {
+              if net = ::/0 then {
                 accept;
               }
               reject;
@@ -90,7 +90,7 @@ in
           table master4;
           peer table vpn4_table;
           export filter {
-            if net ~ [ 0.0.0.0/0 ] then {
+            if net = 0.0.0.0/0 then {
               # Copy default route to vpn4 table
               accept;
             }
@@ -137,7 +137,7 @@ in
         ipv4 {
           export all;
           import filter {
-            if net ~ [ 0.0.0.0/0 ] then {
+            if net = 0.0.0.0/0 then {
               ${(builtins.foldl' (result: gateway: {
                 text = ''
                   ${result.text}
@@ -197,7 +197,7 @@ in
         ipv6 {
           export all;
           import filter {
-            if net ~ [ ::/0 ] then {
+            if net = ::/0 then {
               ${(builtins.foldl' (result: gateway: {
                 text = ''
                   ${result.text}