routing/testdata: ensure test channels have unique chan ID's

This commit fixes a bug in the test data that was uncovered due to the
recent bug fix within the AddChannelEdge method within the ChannelGraph
struct of channeldb.

The storage and assertion of unique channel ID’s wasn’t correct due to
bug in the channeldb which caused the defect in the test data to go
unnoticed.

routing/testdata/basic_graph.json

@@ -72,7 +72,7 @@
         {
 	    "node_1": "032b480de5d002f1a8fd1fe1bbf0a0f1b07760f65f052e66d56f15d71097c01add",
             "node_2": "036264734b40c9e91d3d990a8cdfbbe23b5b0b7ad3cd0e080a25dcd05d39eeb7eb",
-            "channel_id": 11111, 
+            "channel_id": 3495345, 
             "channel_point": "9f155756b33a0a6827713965babbd561b55f9520444ac5db0cf7cb2eb0deb5bc:0", 
             "flags": 0, 
             "expiry": 1,
@@ -84,7 +84,7 @@
         {
             "node_1": "0367cec75158a4129177bfb8b269cb586efe93d751b43800d456485e81c2620ca6",
             "node_2": "03c19f0027ffbb0ae0e14a4d958788793f9d74e107462473ec0c3891e4feb12e99",
-            "channel_id": 11111, 
+            "channel_id": 2340213491, 
             "channel_point": "72cd6e8422c407fb6d098690f1130b7ded7ec2f7f5e1d30bd9d521f015363793:0", 
             "flags": 0, 
             "expiry": 1,
@@ -96,7 +96,7 @@
         {
             "node_1": "0367cec75158a4129177bfb8b269cb586efe93d751b43800d456485e81c2620ca6",
             "node_2": "02e7b1aaac10977c38e9c61c74dc66840de211bcec3021603e7977bc5e28edabfd",
-            "channel_id": 11111, 
+            "channel_id": 689530843, 
             "channel_point": "25376aa6cb81913ad30416bd22d4083241bd6d68e811d0284d3c3a17795c458a:0", 
             "flags": 0, 
             "expiry": 1,
@@ -108,7 +108,7 @@
         {
             "node_1": "02e7b1aaac10977c38e9c61c74dc66840de211bcec3021603e7977bc5e28edabfd",
             "node_2": "03c19f0027ffbb0ae0e14a4d958788793f9d74e107462473ec0c3891e4feb12e99",
-            "channel_id": 11111, 
+            "channel_id": 523452362, 
             "channel_point": "704a5675c91b1c674309a6475fc51072c2913d6117ee6103c9f1b86956bcbe02:0", 
             "flags": 0, 
             "expiry": 1,