Support for creating app-only db by ignoring multiple OS sources

Signed-off-by: Prabhu Subramanian <prabhu@appthreat.com>

pyproject.toml

@@ -1,6 +1,6 @@
 [project]
 name = "appthreat-vulnerability-db"
-version = "5.7.7"
+version = "5.7.8"
 description = "AppThreat's vulnerability database and package search library with a built-in file based storage. OSV, CVE, GitHub, npm are the primary sources of vulnerabilities."
 authors = [
     {name = "Team AppThreat", email = "cloud@appthreat.com"},

vdb/lib/config.py

@@ -6,14 +6,18 @@
 nvd_url = "https://nvd.nist.gov/feeds/json/cve/1.1/nvdcve-1.1-%(year)s.json.gz"
 
 # NVD start year. 2018 is quicker. 2002 is quite detailed but slow
-nvd_start_year = os.getenv("NVD_START_YEAR", 2018)
+nvd_start_year = os.getenv("NVD_START_YEAR", "2018")
+try:
+    nvd_start_year = int(nvd_start_year)
+except ValueError:
+    pass
 
 # GitHub advisory feed url
 gha_url = os.getenv("GITHUB_GRAPHQL_URL", "https://api.github.com/graphql")
 
 # No of pages to download from GitHub during a full refresh
-gha_pages_count = os.getenv("GITHUB_PAGE_COUNT", 2)
-npm_pages_count = os.getenv("NPM_PAGE_COUNT", 2)
+gha_pages_count = os.getenv("GITHUB_PAGE_COUNT", "2")
+npm_pages_count = os.getenv("NPM_PAGE_COUNT", "2")
 
 # DB file dir
 data_dir = os.getenv("VDB_HOME", user_data_dir("vdb"))