fix version number check for build strings such as 10.3 (Ubuntu 10.3-1.pgdg16.04+1)

Author: Jordan Fineberg

bin/check-postgres-replication.rb

@@ -106,6 +106,7 @@ def compute_lag(master, slave, m_segbytes)
 
   def check_vsn(conn)
     pg_vsn = conn.exec("SELECT current_setting('server_version')").getvalue(0, 0)
+    pg_vsn = pg_vsn.split(' ')[0]
     Gem::Version.new(pg_vsn) < Gem::Version.new('10.0') && Gem::Version.new(pg_vsn) >= Gem::Version.new('9.0')
   end