enh: improve runOneLinux and TDTestCase of python test scripts

tests/pytest/util/cases.py

@@ -63,7 +63,7 @@ class TDCases:
 
         tdLog.info("total %d Linux test case(s) executed" % (runNum))
 
-    def runOneLinux(self, conn, fileName, replicaVar):
+    def runOneLinux(self, conn, fileName, replicaVar=1):
         testModule = self.__dynamicLoadModule(fileName)
 
         runNum = 0

tests/system-test/0-others/taosdShell.py

@@ -166,7 +166,7 @@ class TDTestCase:
         # keyDict['c'] = cfgPath
         # keyDict['P'] = self.serverPort
         tdDnodes=cluster.dnodes
-        for i in range(5):
+        for i in range(len(tdDnodes)):
             tdDnodes[i].stoptaosd()