[tree] minor edit in warning message

Author: ferdymercury

roottest/root/tree/index/Dupe.ref

@@ -1,5 +1,5 @@
 
 Processing runDupe.C...
 Error in <TTreeIndex::TTreeIndex>: In entry 1, a duplicate key was found value at (run, event) = (5, 1)
-Warning in <TTreeIndex::TTreeIndex>: Further potential duplicates won't be checked, use gDebug = 1 to check all.
+Warning in <TTreeIndex::TTreeIndex>: Further potential duplicates won't be checked, use gDebug >= 1 to check all.
 (int) 0

tree/treeplayer/src/TTreeIndex.cxx

@@ -219,7 +219,7 @@ TTreeIndex::TTreeIndex(const TTree *T, const char *majorname, const char *minorn
                   i, fMajorName.Data(), fMinorName.Data(), fIndexValues[i], fIndexValuesMinor[i]
                  );
             if (gDebug < 1) {
-               Warning("TTreeIndex", "Further potential duplicates won't be checked, use gDebug = 1 to check all.");
+               Warning("TTreeIndex", "Further potential duplicates won't be checked, use gDebug >= 1 to check all.");
             }
             duplicatedKeys = true;
          }