[Fixed] Download datasheet abort on connection error

- Now it isn't fatal
- This is PR #290 applied to master

Closes #289

CHANGELOG.md

@@ -40,6 +40,8 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 - Problems to compress netlists. (#287)
 - 2D PCB processing didn't show in 3D targets (i.e. solder paste not removed in
   the 3D render). (See #270)
+- KiBot exited when downloading a datasheet and got a connection error
+  (#289 #290)
 
 ### Changed
 - Diff: when comparing a file now the links says Current/FILE instead of None

kibot/out_download_datasheets.py

@@ -68,6 +68,9 @@ class Download_Datasheets_Options(VariantOptions):
                 except requests.exceptions.ReadTimeout:
                     logger.warning(W_FAILDL+'Timeout during download `{}`'.format(ds))
                     return None
+                except requests.exceptions.ConnectionError:
+                    logger.warning(W_FAILDL+'Connection error during download `{}`'.format(ds))
+                    return None
                 except requests.exceptions.SSLError:
                     logger.warning(W_FAILDL+'SSL Error during download `{}`'.format(ds))
                     return None