Fixes leading withespaces in LDFLAGS for libpcap
From: Giuseppe Foti <foti.giuseppe@gmail.com>
Upstream PR: https://github.com/greenbone/boreas/pull/66

--- a/src/CMakeLists.txt
+++ b/src/CMakeLists.txt
@@ -32,6 +32,7 @@ if (PCAP_CONFIG)
   execute_process (COMMAND pcap-config --libs
     OUTPUT_VARIABLE PCAP_LDFLAGS
     OUTPUT_STRIP_TRAILING_WHITESPACE)
+    string(STRIP ${PCAP_LDFLAGS} PCAP_LDFLAGS)
   execute_process (COMMAND pcap-config --cflags
     OUTPUT_VARIABLE PCAP_CFLAGS
     OUTPUT_STRIP_TRAILING_WHITESPACE)