Reporting Mode: Do not attempt to acquire missing data from peer network (#4458)

In Reporting Mode, a server would core dump when it is not able to read
from Cassandra. This patch prevents the core dump when Cassandra is down
for reporting mode servers. This does not fix the root cause, but it
cuts down on some of the resulting noise.

src/test/shamap/common.h

@@ -105,13 +105,15 @@ public:
     }
 
     void
-    missingNode(std::uint32_t refNum) override
+    missingNodeAcquireBySeq(std::uint32_t refNum, uint256 const& nodeHash)
+        override
     {
         Throw<std::runtime_error>("missing node");
     }
 
     void
-    missingNode(uint256 const& refHash, std::uint32_t refNum) override
+    missingNodeAcquireByHash(uint256 const& refHash, std::uint32_t refNum)
+        override
     {
         Throw<std::runtime_error>("missing node");
     }