QGCExternalLibs: Download with Curl and use AIRMAP_PLATFORM_SDK_FILEPATH

Using Curl instead of Wget since I personally have the feeling that is is more widely available as Wget.
Additionally, cleaning up the usage of AIRMAP_PLATFORM_SDK_FILENAME and using  AIRMAP_PLATFORM_SDK_FILEPATH instead with an absolute path.

Signed-off-by: Thomas Karl Pietrowski <thopiekar@gmail.com>

QGCExternalLibs.pri

@@ -297,7 +297,7 @@ contains (DEFINES, DISABLE_AIRMAP) {
     } else:LinuxBuild {
         #-- Download and install platform-sdk libs and headers iff they're not already in the build directory
         AIRMAP_PLATFORM_SDK_URL = "https://github.com/airmap/platform-sdk/releases/download/2.0/airmap-platform-sdk-2.0.0-Linux.deb"
-        AIRMAP_PLATFORM_SDK_FILENAME = "airmap-platform-sdk.deb"
+        AIRMAP_PLATFORM_SDK_FILEPATH = "$${OUT_PWD}/airmap-platform-sdk.deb"
         AIRMAP_PLATFORM_SDK_INSTALL_DIR = "tmp"
 
         airmap_platform_sdk_install.target = $${AIRMAP_PLATFORM_SDK_PATH}/include/airmap
@@ -306,12 +306,12 @@ contains (DEFINES, DISABLE_AIRMAP) {
             mkdir -p "$${AIRMAP_PLATFORM_SDK_PATH}/linux/$${AIRMAP_QT_PATH}" && \
             mkdir -p "$${AIRMAP_PLATFORM_SDK_PATH}/include/airmap" && \
             mkdir -p "$${AIRMAP_PLATFORM_SDK_PATH}/$${AIRMAP_PLATFORM_SDK_INSTALL_DIR}" && \
-            wget -q -O "$${OUT_PWD}/$${AIRMAP_PLATFORM_SDK_FILENAME}" "$${AIRMAP_PLATFORM_SDK_URL}" && \
-            ar p "$${AIRMAP_PLATFORM_SDK_FILENAME}" data.tar.gz | tar xvz -C "$${AIRMAP_PLATFORM_SDK_PATH}/$${AIRMAP_PLATFORM_SDK_INSTALL_DIR}/" --strip-components=1 && \
+            curl --location --output "$${AIRMAP_PLATFORM_SDK_FILEPATH}" "$${AIRMAP_PLATFORM_SDK_URL}" && \
+            ar p "$${AIRMAP_PLATFORM_SDK_FILEPATH}" data.tar.gz | tar xvz -C "$${AIRMAP_PLATFORM_SDK_PATH}/$${AIRMAP_PLATFORM_SDK_INSTALL_DIR}/" --strip-components=1 && \
             mv -u "$${AIRMAP_PLATFORM_SDK_PATH}/$${AIRMAP_PLATFORM_SDK_INSTALL_DIR}/usr/lib/x86_64-linux-gnu/*" "$${AIRMAP_PLATFORM_SDK_PATH}/linux/$${AIRMAP_QT_PATH}/" && \
             mv -u "$${AIRMAP_PLATFORM_SDK_PATH}/$${AIRMAP_PLATFORM_SDK_INSTALL_DIR}/usr/include/airmap/*" "$${AIRMAP_PLATFORM_SDK_PATH}/include/airmap/" && \
             rm -rf "$${AIRMAP_PLATFORM_SDK_PATH}/$${AIRMAP_PLATFORM_SDK_INSTALL_DIR}" && \
-            rm "$${AIRMAP_PLATFORM_SDK_FILENAME}"
+            rm "$${AIRMAP_PLATFORM_SDK_FILEPATH}"
         airmap_platform_sdk_install.depends =
         QMAKE_EXTRA_TARGETS += airmap_platform_sdk_install
         PRE_TARGETDEPS += $$airmap_platform_sdk_install.target