build: fix path

Signed-off-by: Athan <[email protected]>

Author: kgryte

lib/node_modules/@stdlib/stats/base/dists/planck/mode/include.gypi

@@ -24,7 +24,7 @@
   # Define variables to be used throughout the configuration for all targets:
   'variables': {
     # Source directory:
-    'src_dir': ' ./src',
+    'src_dir': './src',
 
     # Include directories:
     'include_dirs': [