exists method call is broken (#1432)

Issues:
Fixes #1431

Problem:
The exists method was incorrectly calling the load method

Analysis:
this patch fixes the method call

Tests:

Author: caphrim007

f5/bigip/tm/security/log.py

@@ -99,7 +99,7 @@ def exists(self, **kwargs):
         if LooseVersion(self.tmos_ver) == LooseVersion('11.6.0'):
             return self._exists_11_6(**kwargs)
         else:
-            return super(Application, self)._load(**kwargs)
+            return super(Application, self)._exists(**kwargs)
 
     def _exists_11_6(self, **kwargs):
         """Check rule existence on device."""
@@ -174,7 +174,7 @@ def exists(self, **kwargs):
         if LooseVersion(self.tmos_ver) == LooseVersion('11.6.0'):
             return self._exists_11_6(**kwargs)
         else:
-            return super(Network, self)._load(**kwargs)
+            return super(Network, self)._exists(**kwargs)
 
     def _exists_11_6(self, **kwargs):
         """Check rule existence on device."""
@@ -249,7 +249,7 @@ def exists(self, **kwargs):
         if LooseVersion(self.tmos_ver) == LooseVersion('11.6.0'):
             return self._exists_11_6(**kwargs)
         else:
-            return super(Protocol_Dns, self)._load(**kwargs)
+            return super(Protocol_Dns, self)._exists(**kwargs)
 
     def _exists_11_6(self, **kwargs):
         """Check rule existence on device."""
@@ -324,7 +324,7 @@ def exists(self, **kwargs):
         if LooseVersion(self.tmos_ver) == LooseVersion('11.6.0'):
             return self._exists_11_6(**kwargs)
         else:
-            return super(Protocol_Sip, self)._load(**kwargs)
+            return super(Protocol_Sip, self)._exists(**kwargs)
 
     def _exists_11_6(self, **kwargs):
         """Check rule existence on device."""