unifying month format across all bib files (#5286)

Author: omer-rotem1

Diff for: src/test/resources/org/jabref/logic/importer/fileformat/RisImporterTest3.bib

@@ -5,7 +5,7 @@ @incollection{
   issn = {978-1-4822-5326-9},
   journal = {Dermoscopy Image Analysis},
   number = {0},
-  month = {#sep#},
+  month = sep,
   pages = {1-22},
   publisher = {CRC Press},
   series = {Digital Imaging and Computer Vision},

Diff for: src/test/resources/org/jabref/logic/importer/fileformat/RisImporterTestDate1.1.bib

@@ -4,12 +4,12 @@ @article{
     doi = {10.1063/1.1954747},
     issn = {0021-9606},
     journal = {J. Chem. Phys.},
-    month = {#jul#},
+    month = jul,
     number = {3},
     pages = {034708},
     publisher = {American Institute of Physics},
     title = {Hydration forces between silica surfaces: Experimental data and predictions from different theories},
     url = {https://doi.org/10.1063/1.1954747},
     volume = {123},
     year = {2005}
-}
+}

Diff for: src/test/resources/org/jabref/logic/importer/fileformat/RisImporterTestDate1.2.bib

@@ -4,12 +4,12 @@ @article{
     doi = {10.1063/1.1954747},
     issn = {0021-9606},
     journal = {J. Chem. Phys.},
-    month = {#jul#},
+    month = jul,
     number = {3},
     pages = {034708},
     publisher = {American Institute of Physics},
     title = {Hydration forces between silica surfaces: Experimental data and predictions from different theories},
     url = {https://doi.org/10.1063/1.1954747},
     volume = {123},
     year = {2005}
-}
+}