qc_sqlite: Handle a name like ``a.

query_classifier/qc_sqlite/sqlite-src-3110100/src/util.c

@@ -220,7 +220,13 @@ int sqlite3Dequote(char *z){
   for(i=1, j=0;; i++){
     assert( z[i] );
 #ifdef MAXSCALE
-    if ( z[i]=='\\' ){
+    if ( z[i]==0 ){
+      // TODO: This is needed only because exposed_sqlite3Dequote() is called
+      // TODO: in qc_sqlite.c:update_names(). That call probably is not needed
+      // TODO: and should be removed, in which case this check could also be
+      // TODO: removed.
+      break;
+    }else if ( z[i]=='\\' ){
       z[j++] = '\\';
       if ( z[i+1]==quote || z[i+1]=='\\' ){
         z[j++] = quote;