Update GLM_linear.ipynb to correct the URL for statsmodels on sourceforge

Author: seyedrezamirkhani

docs/source/learn/core_notebooks/GLM_linear.ipynb

@@ -334,7 +334,7 @@
    "cell_type": "markdown",
    "metadata": {},
    "source": [
-    "Much shorter, but this code does the exact same thing as the previous specification (you can change priors and everything else too if we wanted). `bambi` parses the `formulae` model string, adds random variables for each regressor (`Intercept` and slope `x` in this case), adds a likelihood (by default, a Normal is chosen), and all other variables (`sigma`). Finally, `bambi` then initializes the parameters to a good starting point by estimating a frequentist linear model using [statsmodels](http://statsmodels.sourceforge.net/devel/).\n",
+    "Much shorter, but this code does the exact same thing as the previous specification (you can change priors and everything else too if we wanted). `bambi` parses the `formulae` model string, adds random variables for each regressor (`Intercept` and slope `x` in this case), adds a likelihood (by default, a Normal is chosen), and all other variables (`sigma`). Finally, `bambi` then initializes the parameters to a good starting point by estimating a frequentist linear model using [statsmodels](http://statsmodels.sourceforge.net/).\n",
     "\n",
     "If you are not familiar with R's syntax, `'y ~ x'` specifies that we have an output variable `y` that we want to estimate as a linear function of `x`."
    ]