blockchain_import: more informative verification switch

src/blockchain_utilities/blockchain_import.cpp

@@ -594,8 +594,8 @@ int main(int argc, char* argv[])
   const command_line::arg_descriptor<std::string> arg_database = {
     "database", available_dbs.c_str(), default_db_type
   };
-  const command_line::arg_descriptor<bool> arg_verify =  {"verify",
-    "Verify blocks and transactions during import", true};
+  const command_line::arg_descriptor<bool> arg_verify =  {"guard-against-pwnage",
+    "Verify blocks and transactions during import (only disable if you exported the file yourself)", true};
   const command_line::arg_descriptor<bool> arg_batch  =  {"batch",
     "Batch transactions for faster import", true};
   const command_line::arg_descriptor<bool> arg_resume =  {"resume",