Fix retry exception for Device command extract

* The previous code did not handle the retry correctly

core/ArchiveExtractor.py

@@ -447,7 +447,7 @@ class ArchiveExtractor:
             None if failed after the amount of retries.
         """
 
-        for i in range(retry-1):
+        for i in range(retry):
             # Make retrieval request
             self.logger.debug("Execute %s (%s)"%(cmd, arg))
             try:
@@ -455,12 +455,12 @@ class ArchiveExtractor:
             except tango.DevFailed as e:
                 self.logger.warning("The extractor device returned the following error:")
                 self.logger.warning(e)
+                if  i == retry-1:
+                    logger.error("Could not execute command %s (%s). Check the device extractor"%(cmd, arg))
+                    return None
                 self.logger.warning("Retrying...")
                 continue
             break
-        if i==2:
-            logger.error("Could not execute command %s (%s). Check the device extractor"%(cmd, arg))
-            return None
         return cmdreturn