Allow crash handler to propagate signal.

include/backward.hpp

@@ -4225,7 +4225,7 @@ private:
             raise(info->si_signo);
 
             // terminate the process immediately.
-            puts("watf? exit");
+            puts("wat? exit");
             _exit(EXIT_FAILURE);
         }
     };

src/main/typesense_server.cpp

@@ -86,7 +86,6 @@ void crash_callback(int sig, backward::StackTrace& st) {
     }
 
     LOG(ERROR) << "Typesense " << TYPESENSE_VERSION << " is terminating abruptly.";
-    exit(-1);
 }
 
 int main(int argc, char **argv) {