more strncmp simplify

Author: scivision

+stdlib/canonical.m

@@ -31,7 +31,7 @@
   return
 end
 
-if ispc && startsWith(c, "\\")
+if ispc && strncmp(c, "\\", 2)
   % UNC path is not canonicalized
   return
 end

+stdlib/normalize.m

@@ -25,7 +25,7 @@
   % use split to remove /../ and /./ and duplicated /
   parts = split(n, '/');
   i0 = 1;
-  if startsWith(n, "/")
+  if strncmp(n, "/", 1)
     n = "/";
   elseif ispc && strlength(n) >= 2 && strlength(stdlib.root_name(p))
     n = parts(1);