app-layer: fix ippair memcap counters

Fixed counter for ippair.memcap by using the correct function,
IPPairGetMemcap.
Until now IPPairGetMemuse was used both for memuse and memcap.

Ticket: 7827

src/app-layer.c

@@ -1166,7 +1166,7 @@ void AppLayerRegisterGlobalCounters(void)
     StatsRegisterGlobalCounter("http.byterange.memuse", HTPByteRangeMemuseGlobalCounter);
     StatsRegisterGlobalCounter("http.byterange.memcap", HTPByteRangeMemcapGlobalCounter);
     StatsRegisterGlobalCounter("ippair.memuse", IPPairGetMemuse);
-    StatsRegisterGlobalCounter("ippair.memcap", IPPairGetMemuse);
+    StatsRegisterGlobalCounter("ippair.memcap", IPPairGetMemcap);
     StatsRegisterGlobalCounter("host.memuse", HostGetMemuse);
     StatsRegisterGlobalCounter("host.memcap", HostGetMemcap);
 }