Remove leftovers from gpcheck deprecation

gpcheck was deprecated in 4.3.6.0 but the configuration file was
never removed. Clean out together with install rule.

Reported by zhangyuvip

gpAux/Makefile

@@ -1064,8 +1064,6 @@ mkplatform:
 	@cd $(PLATFORM) && $(MAKE)
 	cp -p platform/gpnetbench/gpnetbenchServer $(INSTLOC)/bin/lib
 	cp -p platform/gpnetbench/gpnetbenchClient $(INSTLOC)/bin/lib
-	mkdir -p $(INSTLOC)/etc
-	cp -p platform/gpcheck/gpcheck.cnf $(INSTLOC)/etc/
 
 copydocs :
 	@if [ ! -d $($INSTLOC)/docs ] ; then mkdir -p $(INSTLOC)/docs; fi

gpAux/platform/gpcheck/gpcheck.cnf

-[global]
-configfile_version = 3
-
-[linux]
-xfs_mount_options = rw,noatime,inode64,allocsize=16m
-sysctl.kernel.shmmax = 500000000
-sysctl.kernel.shmmni = 4096
-sysctl.kernel.shmall = 4000000000
-sysctl.kernel.sem = 250 512000 100 2048
-sysctl.kernel.sysrq = 1
-sysctl.kernel.core_uses_pid = 1
-sysctl.kernel.msgmnb = 65536
-sysctl.kernel.msgmax = 65536
-sysctl.kernel.msgmni = 2048
-sysctl.net.ipv4.tcp_syncookies = 1
-sysctl.net.ipv4.ip_forward = 0
-sysctl.net.ipv4.conf.default.accept_source_route = 0
-sysctl.net.ipv4.tcp_tw_recycle = 1
-sysctl.net.ipv4.tcp_max_syn_backlog = 4096
-sysctl.net.ipv4.conf.all.arp_filter = 1
-sysctl.net.ipv4.ip_local_port_range = 1025 65535
-sysctl.net.core.netdev_max_backlog = 10000
-sysctl.vm.overcommit_memory = 2