hnswalg.h: reduce M cap further to 10000

per comment in merge request discussion.

Author: emollier

hnswlib/hnswalg.h

@@ -101,12 +101,12 @@ class HierarchicalNSW : public AlgorithmInterface<dist_t> {
         data_size_ = s->get_data_size();
         fstdistfunc_ = s->get_dist_func();
         dist_func_param_ = s->get_dist_func_param();
-        if ( M <= 100000 ) {
+        if ( M <= 10000 ) {
             M_ = M;
         } else {
-            std::cerr << "warning: M parameter exceeds 100000 which may lead to adverse effects." << std::endl;
-            std::cerr << "         Cap to 100000 will be applied for the rest of the processing." << std::endl;
-            M_ = 100000;
+            std::cerr << "warning: M parameter exceeds 10000 which may lead to adverse effects." << std::endl;
+            std::cerr << "         Cap to 10000 will be applied for the rest of the processing." << std::endl;
+            M_ = 10000;
         }
         maxM_ = M_;
         maxM0_ = M_ * 2;